WO2008118504A2 - Semi-automatic and automatic firearm, bolt and barrel sub assemblies therefor and method of making same - Google Patents

Abstract

An autoloading gas operated firearm of the 'bull pup' configuration capable of semi-automatic and automatic fire. Provision is made for quick release barrel interchange; and, a barrel with an integrally formed suppressor with internal discharge/venting of the gas operating chamber is described. The surfaces of sliding engagement with the bolt and bolt earner are hard coated for wear resistance making lubrication unnecessary. The sight structure is positively registered. The sight retaining knobs may be tightened with a cartridge case. The sliding surfaces of the receiver and bolt carrier are fluted for dirt collection; and, the bolt carrier tubes and stock are provided with water drain holes enabling ready firing after water immersion. A safety is described on opposite sides of the firearm with all-around readily visible indicia of firing status. The magazine engagement is uniquely configured to prevent usage of non specific ammunition.

Description

SEMI-AUTOMATIC AND AUTOMATIC FIREARM, BOLT AND BARREL SUB ASSEMBLIES THEREFOR AND METHOD OF

MAKING SAME

[0001] The present application claims the benefit of U.S. Provisional Application No. 60/879,752, filed January 10, 2007, which is incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

[0002] The present disclosure relates to a firearm with a rearwardly sliding breechblock and more particularly to an autoloading firearm of a type usable by the military.

BACKGROUND

[0003] A lightweight firearm capable of firing either in the semi-automatic mode or the automatic mode is used by many militaries as the primary infantry weapon. Militaries also use weapons optimized for fully automatic mode fire as light machine guns. Additionally, militaries also use firearms optimized for long range accuracy for use as sniper weapons.

[0004] One weapon used by various military organizations is the M-16 rifle. The M-16 is a gas operated autoloading weapon and can operate as a semi-automatic weapon or an automatic weapon. It has a stock which supports a receiver and breechblock with a barrel extending from the forward end of the receiver. The trigger is below the receiver and breechblock with a magazine and firing chamber forward (toward the muzzle) of the trigger.

[0005] Another design for firearms which can operate in either the semiautomatic or automatic mode is called the "bull pup" configuration. In a bull pup firearm, a stock supports a receiver and breechblock with a barrel extending from the front of the receiver. However, the trigger is located near the front of the receiver with the magazine and firing chamber behind the trigger. This provides an overall shorter weapon when compared to a conventional design having the same barrel length. An example of a semi/full automatic firearm having a "bull-pup" configuration with the trigger located in front of the magazine is the Steyr model AUG which was manufactured in the 1970's.

[0006] In military usage an infantry squad may consist of several soldiers carrying standard assault rifles such as the M16 having semi-automatic, burst and full automatic capabilities. One or more members of the squad may be carrying a weapon adapted to the sniper mode; and, one or more members of the squad may be carrying a weapon adapted to the light machine gun mode. These weapons frequently are significantly different from one another in their appearance and in their major components. This creates several disadvantages. In a combat situation, a soldier carrying a light machine gun or a soldier carrying sniper weapons may be a primary target. If his weapon identifies him at a distance, an enemy may focus fire on him. Also, if the three types of weapons use different operating components, a weapon with a failed component may be out of action until a new component can be obtained. If the weapon is a specialized weapon such as a light machine gun and the squad only has one light machine gun, this capability is removed until a replacement is obtained.

[0007] Reliability has been a concern with military firearms. These firearms are used in hostile environments where sand, dust, dirt, water and other contaminants can enter the firearm. Moreover, lubricants are used with many firearms which are subjected to hot, high pressure gasses and firing debris in the weapon or a mixture of lubricant and foreign matter in the weapon during firing. A firearm may fail, jam, or become more difficult to operate because of foreign matter. [0008] Some firearms have sights or sighting devices removably attached to the weapon. Maintaining proper alignment of the sight or sighting device and the weapon itself has been found to be difficult. The point at which the sight is mounted to the weapon can wear resulting in less than a tight fit. The fasteners or other means holding the sight onto the weapon can become loose or sloppy. Heretofore the most widely used technique for attachment of the sight involved sliding engagement of corresponding surfaces on the sight and the firearm, which surfaces are subject to looseness due to tolerances and wear. [0009] In addition, the controls such as Mode (full auto, burst, single shot) Selector switches, Safetys and the like on existing weapons have been difficult to reach; and, it has been found difficult to readily determine the operating mode of the firearm from looking at the position of the selector switch. Moreover, difficulties have been encountered in disassembly of the weapon, particularly where special tools are required. Components which should be easily removed cannot be removed. Items which should be adjustable in the field can only be adjusted with great difficulty. [0010] In operating military weapons in the full automatic Mode for sustained operation, problems have been encountered with heating of the parts; and, temperatures in excess of 400⁰F have been experienced, resulting in stoppages due to frictional seizures of the bolt mechanism and failure of gas seals in gas operated firearms.

[0011] Additionally, the moving parts of a firearm often have been subject to deterioration and wear when subjected to sustained use resulting in less than optimal performance.

[0012] In military usage, particularly for use as a sniper weapon, it is essential that the sound of the muzzle blast be suppressed; and, this has necessitated the use of silencers or sound suppressors. For military use at night, it is desirable to suppress not only the muzzle discharge flash, but also the gas operating chamber vent or exhaust flash.

[0013] Heretofore, sound suppressors have been attached in the field over the existing barrel muzzle as an accessory to the basic weapon. For gas operated autoloading weapons, the sound suppressor, while reducing muzzle sound and flash, has caused an increase in the pressure build-up in the gas operating piston chamber, which has resulted in an increase in the flash discharge from the gas operating chamber exhaust vent thereby rendering the weapon unstealthy for night firing. Furthermore, the increased pressure in the gas operating piston chamber has resulted in increased operating piston and operating rod velocity; and, in the automatic mode has increased the cyclic rate of fire which, in turn, has created greater forces or loads on the bolt cam and other components of the moveable breechblock assembly and in some cases has resulted in jamming and premature failure of these parts.

[0014] Thus, it has been desired to find a way or means of suppressing firing sound and flash without altering the basic operating characteristics of a gas operated autoloading weapon.

[0015] Another problem encountered in military usage of gas operated autoloading weapons with sustained operation in both the semi-automatic and automatic modes, is cartridge jamming when the bolt is moved forward to chamber the round. The most common form of cartridge jamming is that of cartridge misalignment as it exits the magazine and is caused by the force of the bolt catching the cartridge rim and angling the round, causing the nose of bullet to catch against the end of the barrel surrounding the cartridge chamber opening. In order to unjam the weapon such as an M-16, it often has been necessary to disassemble the breechblock and bolt carrier mechanism to remove the jammed round. Thus, it has been desired to improve the operation of a gas piston operated autoloading weapon in a manner that eliminates cartridge jamming during sustained firing.

SUMMARY

[0016] In accordance with the present disclosure, a compact firearm of the "bullpup" configuration, capable of operating in the semi-automatic, burst, and full automatic modes is described.

[0017] In an exemplary embodiment, an improved structure for mounting a sight or sighting device uses bosses on the top of the receiver, which are received in matching recesses on the bottom of the sight or sighting device, so that the sight or sighting device may be placed directly upon the receiver in its intended position without any need of sliding engagement. Once placed, the sight or sighting device is fixed to the receiver by means of rotatable fasteners captured on the sighting device. [0018] Further in accordance with the present disclosure, the rotatable fasteners fixing the sighting device to the receiver of the firearm are provided with an enlarged head having a flat top and a cylindrical side wall with holes in the side wall matching the dimensions of the smaller end of the cartridge case for a round of ammunition to be used in the weapon which may be used as a tool for tightening the fastener. [0019] Yet further in accordance with the disclosure, the fasteners fixing the sight or sighting device to the weapon are provided with slots across the top surface of the head of the fastener which match the dimensions of the base rim of the cartridge case of a round of ammunition to be used in the weapon.

[0020] Further in accordance with the disclosure, an accessory rail mounting is provided on the weapon including bosses having recesses at their center, with the recesses accepting fasteners identical to those holding the sighting device on the top of the weapon.

[0021] Yet further in accordance with the disclosure, a firearm is provided comprising a stock having a magazine opening adapted to receive a magazine, a receiver adjacent the stock, a barrel adjacent the receiver, a trigger longitudinally located between the magazine opening and the firearm muzzle and a bolt carrier having guide tubes which ride upon guide rods fixed to the stock and ride within bores in the receiver; the interior of the receiver bore and the interior of the guide tubes being provided with longitudinal grooves along their length to expel water. [0022] Yet further in accordance with the disclosure, a firearm is provided with a bolt catch release lever on the stock separate from the operating lever of the bolt. [0023] Yet further in accordance with the disclosure, a firearm is provided having a safety actuator movable transversely with respect to the barrel of the weapon having red markings visible from the front, rear, top and bottom of the weapon when the safety is in the fire position and white markings visible from the front, rear, top and bottom of the weapon when the safety is in the safe position. [0024] Further in accordance with the disclosure, a gas operated firearm is provided with an adjustable gas block with raised dots and raised letters indicating the selected setting for operation of the weapon.

[0025] Still further in accordance with the disclosure, a firearm is provided having a two stage trigger and a selector switch; the selector switch having a full automatic position and a burst position, the selector switch being accessible from the exterior of the weapon, such that a user may move the selector switch to a full automatic position in which a single shot may be fired by pressing the trigger to a first position and multiple shots in full automatic mode may be fired by pressing the trigger to a second position; and, a user may move the selector to a burst position in which a single shot may be fired by pressing the trigger to a first position and a burst of a preselected number of shots in a burst made may be fired by pressing the trigger to a second position.

[0026] Yet further in accordance with the disclosure, a firearm is provided having a magazine adapted to contain several rounds of ammunition and dispense the rounds of ammunition through a top opening with an ammunition retaining projection; the magazine being provided with longitudinal and transverse reinforcing ribs adjacent the sides ribs with a recess provided in the ribs at a location allowing the magazine to be inserted into the magazine opening of the firearm with a protrusion extending into the magazine opening fitting through the recess.

[0027] Yet further in accordance with the disclosure, a forward assist button is provided on the firearm forward of the front surface of the bolt.

[0028] Yet further in accordance with the disclosure, the bolt carrier is provided with two rollers at its top, the rollers engaging a downwardly facing surface.

[0029] Yet further in accordance with the disclosure, surfaces coming into sliding contact with other surfaces during operation of the firearms are micro-finished and coated for wear and friction resistance.

[0030] The exemplary embodiment disclosed provides a reliable firearm which can be operated as a standard semi-automatic infantry weapon, a sniper weapon, and a light machine gun while maintaining similarities of appearance and interchangeability of many parts.

[0031] The disclosure describes a firearm which provides precise alignment between an attached sighting device and the firearm itself; and, can maintain precise alignment is maintained when the sighting device is dismounted and remounted on the firearm.

[0032] This disclosure describes a firearm with a sight or setting device which can be mounted on the firearm without sliding. [0033] An exemplary embodiment of the disclosed firearm has a sight or sighting device which can be mounted on the firearm by means of rotatable fasteners which can be rotated by use of the cartridge case for a round of ammunition for the firearm. [0034] A firearm is described herein which can use ammunition only in magazines designed for the firearm.

[0035] The present disclosure describes a firearm which can be easily switched from full automatic to burst mode without disassembling the firearm. [0036] The present disclosure describes a firearm with a forward assist button for closing the bolt which is mounted forward on the weapon so that it may be easily and quietly used.

[0037] A firearm is described herein having sliding surfaces which are micro- finished and coated to minimize friction whereby the firearm may be operated in a lubricant free state.

[0038] A firearm is described herein having a quickly removable sling. [0039] A firearm is described herein with a sighting scope with adjustment markings using both arrows and roman letters so as to be understandable to all. [0040] The present disclosure also describes a unique quick-change integral barrel and sound/flash suppressor for a gas operated autoloading weapon which is readily interchangeable with the basic weapon barrel without requiring disassembly of the weapon and which is effective to reduce muzzle blast and flash and also internally suppresses flash from the gas operating piston chamber without increasing the pressure therein. Therefore, the suppressor does not increase the operating piston velocity or change the cyclic rate of fire in the automatic mode. [0041] The present disclosure also describes a bolt assembly or breechblock for an autoloading weapon wherein the face of the bolt has a centering recess therein for receiving the rim flange end of the cartridge; and, the surface of the end of the bolt surrounding the recess is inclined or tapered for guiding the cartridge rim into the recess for preventing misalignment of the cartridge and jamming upon forward movement of the bolt.

[0042] The present disclosure also describes a bolt assembly with an ejector pin spring biased with spring material able to withstand temperatures of about 800^gF. The disclosure also describes a bolt assembly for an autoloading firearm with an extractor spring-biased with plural nested coil springs.

[0043] The present disclosure describes a gun stock barrel and receiver assembly for an autoloading firearm with a stock with a pair of spaced tubes having the bolt carrier slidably disposed thereon, the tubes having a plurality of apertures formed therein; and, channels or openings are formed in the interior ribs and lower rim of stock for facilitating rapid draining upon surfacing of the weapon after immersion in water.

[0044] The firearm described in the present disclosure is capable of being rapidly converted for firing different caliber cartridges by interchanging only the barrel, bolt assembly and magazine.

[0045] The disclosure describes a bolt assembly for a gas operated autoloading firearm wherein the bolt has a cam pin formed of an alloy with Chromium,

Manganese and Molybdenum having a yield strength of 220 Ksi (1518 KPa) and a hardness of about 52 on the Rockwell "C" scale.

[0046] The present disclosure also describes a gas operated autoloading firearm with an adjustable exhaust for the operating piston chamber having Braille-type raised indicia for tactile identification of the selected exhaust setting.

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIGURE 1 is an exploded view of the firearm of the present disclosure;

[0048] FIGURE 2 is a view from the right front of the assembled firearm of the present disclosure;

[0049] FIGURE 3 is a view of the assembled firearm of the present disclosure from the left front;

[0050] FIGURE 4 is a partial view of the assembled firearm of the present disclosure taken from the left rear;

[0051] FIGURE 5 is an enlarged view of the receiver of the present firearm;

[0052] FIGURE 6 is an enlarged view of the gun lock subassembly of the present firearm;

[0053] FIGURE 7 is a front view of the receiver of FIGURE 5; [0054] FIGURE 8 is a view of the bolt carrier of the firearm of FIGURE 1 ;

[0055] FIGURE 9 is a rear view of the gas cylinder member of the present firearm;

[0056] FIGURE 10 is a front view of the gas cylinder of FIGURE 9;

[0057] FIGURE 11 is a side view of the magazine for the firearm of FIGURE 1 ;

[0058] FIGURE 12 is a partial view of the magazine of FIGURE 11 showing the engagement surfaces;

[0059] FIGURE 13 is an under view of the magazine receptacle of the stock of the firearm of FIGURE 1 ;

[0060] FIGURE 14 is a side elevation view showing bolt, bolt carrier, firing pin assembly and hammer;

[0061] FIGURE 15 is a view showing the attachment of the sighting structure to the magazine taken from below the sighting structure;

[0062] FIGURE 16 is a view similar to FIGURE 15 taken from above the receiver and the sighting structure;

[0063] FIGURE 17 is a view showing the sighting structure attached to the receiver;

[0064] FIGURE 18 is a side view of the fastener employed in the attachment of

FIGURE 17;

[0065] FIGURE 19 is a view of the fastener of FIGURE 18 taken from above the fastener head;

[0066] FIGURE 20 is view of the sling attachment fitting;

[0067] FIGURE 21 is a section view taken along section indicating line A-A of

FIGURE 20;

[0068] FIGURE 22 is a section view taken along section indicating line B-B of

FIGURE 5;

[0069] FIGURE 23 is an axonometric view of a cartridge bolt assembly for an autoloading firearm such as shown in FIGURE 1 ;

[0070] FIGURE 24 is an exploded view of the bolt assembly of FIGURE 23;

[0071] FIGURE 25 is a section view taken along section indicating lines 25-25 of

FIGURE 23; [0072] FIGURE 26 is an enlarged view of a portion of FIGURE 25;

[0073] FIGURE 27 is a side elevation view of a one-piece barrel and suppressor assembly;

[0074] FIGURE 28 is a section view taken along section indicating lines 28-28 of

FIGURE 27;

[0075] FIGURE 29 is a muzzle end view of the barrel and suppressor assembly of FIGURE 27;

[0076] FIGURE 30 is a section view taken along section indicating lines 30-30 of

FIGURE 29;

[0077] FIGURE 31 is a broken away view of the stock 16 of the firearm of

FIGURE 1 ;

[0078] FIGURE 32 is an enlarged view of a portion of FIGURE 31 ;

[0079] FIGURE 33 is a view similar to FIGURE 31 and shows the bolt locking mechanism;

[0080] FIGURE 34 is an enlarged view of a portion of FIGURE 33;

[0081] FIGURE 35 is a view of a broken away portion of the stock 16 for the firearm of FIGURE 1 ;

[0082] FIGURE 36 is an enlarged view of a rearward portion of the stock of

FIGURE 35;

[0083] FIGURE 37 is an enlarged view of a lower portion of the rearward section of the stock of FIGURE 35;

[0084] FIGURE 38 is an enlarged view of a forward portion of the stock of

FIGURE 35;

[0085] FIGURE 39 is an axonometric view of a site adjustment knob assembly for the site of the firearm of FIGURE 1 ; and

[0086] FIGURE 40 is an exploded view of the knob of FIGURE 39 as viewed from above the horizontal;

[0087] FIGURE 41 is a view similar to FIGURE 40 as viewed from below the horizontal;

[0088] FIGURE 42 is an axonometric view of the firing pin and lock assembly for the firearm of FIGURE 1 ; [0089] FIGURE 43 is an enlarged axonometric view of a portion of the forward hand grip assembly of the firearm of FIGURE 1 ;

[0090] FIGURE 44 is an exploded view of the hand grip assembly of FIGURE 43;

[0091] FIGURE 45 is a view from above and from the right of the firearm of

FIGURE 1 , with the sight removed, showing the right hand ejection port cover in place before locking;

[0092] FIGURE 46 is a view similar to FIGURE 45 showing the ejection port cover locked; and,

[0093] FIGURE 47 is a detailed view of the ejection port cover of FIGURE 45.

DETAILED DESCRIPTION

[0094] Referring to FIGURE 1 , the firearm of the present disclosure is shown in exploded view and includes a stock subassembly indicated generally at 10, a gunlock subassembly indicated generally at 20, a barrel subassembly indicated generally at 30, a receiver subassembly indicated generally at 40, a magazine indicated generally at 50, a trigger mechanism indicated generally at 60, and a butt plate 12.

[0095] Referring to FIGURES 2 and 6, the gunlock subassembly 20 includes a bolt carrier 22 which has a tube 24 attached to the right side thereof and extending longitudinally forward therefrom and a second guide tube 26 extending forward therefrom in spaced parallel relationship with tube 24. Tube 24 has a piston 25 attached to the forward end thereof. The subassembly 20 is inserted into a cavity 14 formed in stock 16; and, the hollow tubes 24, 26 are slidably received over a correspondingly disposed pair of spaced parallel rods provided within the stock 16, which rods are not illustrated in FIGURE 1. Each of the tubes 24, 26 is received in a bore formed in the carrier 22, for a portion of the length of the respective bore; and, the tubes 24, 26 are secured therein by a suitable expedient, as, for example weldment.

[0096] The barrel subassembly 30 is then assembled by having threads 32 on the rear end of the barrel 34 engaging corresponding threads provided in the bore 42 formed on the receiver 44, As is known in the art, threads 32 may have slots therein for quick insert twist lock with correspondingly slotted threads in the bore 42. [0097] The magazine assembly is then inserted into the stock for engaging attachment surfaces in the receiver therein as will hereinafter described in detail. [0098] The trigger mechanism 60 is then inserted into the butt end of the stock and retained therein by a suitable pin or fastener 18 and covered by the butt plate 12.

[0099] Referring to FIGURES 2, 9 and 10, a gas cylinder member 70 is shown and has a gas cylinder or bore 72 formed therein which has the piston end 25 of the tube 24 received therein at a gas plug 75 secured in the end of the bore 72 as shown in FIGURE 2 and adjustable for metering pressurized gas to the piston 25. It will be understood that a barrel 34 is received through a mounting bore 74 formed in the gas cylinder member. The gas cylinder member 70 has a mounting flange 77 extending therefrom at the rearward end, with apertures 79 formed therein for receiving mounting bolts 73 (see FIGURE 3) for attachment to receiver 44. [00100] As shown in FIGURES 9 and 10, different sized gas piston chamber exhaust parts 71 , 73 are provided in the gas piston chamber or cylinder such that upon user rotation of plug 75 (see FIGURE 2), the port size desired for the higher or lower rate of gas chamber venting or discharge is selected. Heretofore, the larger port has been selected when a muzzle suppressor was attached. Additionally, raised indicia denoted by the letters "H" and "S" are provided on the exterior of the gas cylinder to facilitate, in the manner of "Braille," tactile discernment of the desired position of plug 75.

[00101] As is known in the art, the barrel has a small aperture formed therein which communicates with a passage (not shown) formed interiorly of the member 70 to communicate bore 74 with the piston 72 such that upon passage of a round through the muzzle pressurized gas from the barrel flows through the unshown aperture to the bore 72 and acts upon the end of the piston 25 to move the bolt carrier 22 toward the rear or butt end of the firearm. Thus, the firearm of the present disclosure is of the type commonly referred to as gas operated autoloader. The gun lock subassembly 20 is shown in greater detail in FIGURE 6; and, the bolt carrier 22 is shown in enlarged detail in FIGURE 8. In FIGURE 6, the rod 24 is shown with the piston 25 removed; and, the rod 26 is shown with the end plug removed therefrom. [00102] The bolt carrier 22 has a cam slot 27 formed in the top surface thereof for contacting an effecting rearward and rotary movement of the bolt by engaging pin 208 extending vertically upwardly from the bolt which it will be understood is captured within the bolt carrier 22. The bolt carrier 22 has a pair of spaced rollers 29 disposed adjacent the ends thereof and positioned to contact the bolt and provide guidance for the longitudinal movement of the bolt.

[00103] Referring to FIGURES 23-26, the bolt assembly is indicated generally at 200 and is shown assembled in FIGURE 23 and in exploded view in FIGURE 24. The assembly 200 includes bolt 202 which has a longitudinal slot 204 formed in the upper side thereof with an extractor lever 206 pivotally mounted therein by a cross pin 208 received through apertures 209, 210 in the bolt 202 and aperture 212, in the extractor 206. Extractor 206 is pivotally moved during rearward movement of the bolt carrier 22 and bolt 202; and, is spring biased by springs 214, 216, which in the illustrated exemplary embodiment comprise plural nested coil springs. [00104] The bolt cam pin 220 is received in apertures 222, 224 in bolt 202. In the present practice, in an exemplary embodiment, cam pin 220 is formed of material having a yield strength of about 220 Ksi (1518 KPa) such as for example a Chromium, Manganese, Molybdenum alloy steel; however, other suitable materials may be used. In the illustrated exemplary embodiment, the pin is hard plated 0.0005 in (0.013 mm) with Chromium. The bolt 202 has an ejector pin 226 extending axially from the cartridge recess 228 formed in the forward end of the bolt. Pin 226 is biased forward by a spring 228 which is formed of material capable of withstanding operating or service temperatures of 800³F such as, for example, precipitation hardened 17-7 type stainless steel. It will be understood that bolt 202 has a central bore 230 for receiving a firing pin (not shown).

[00105] Referring to FIGURES 25 and 26, the cartridge-receiving recess 228 is shown in greater detail and has the end face 232 of the bolt surrounding the recess 228 inclined at an angle normal to the axis of the firing pin bore 230, by an angle Φ of about 5³. The inclined face 232 serves to "cam" the rim of the cartridge into recess 228 thereby centering the cartridge for movement by the bolt into the firing chamber. In the exemplary embodiment shown in FIGURE 26, the cylindrical side wall of recess 228 is also tapered by an angle θ of about 5⁹ to aid cartridge centering.

[00106] Referring to FIGURE 24, the bolt assembly also includes a seal ring 234 for sealing about springs 214, 216. In an exemplary embodiment, seal 234 is formed of copolymers such as for example one of tetrafluorethylene/polypropylene and ethylene/perfluoromethyl vinylether/tetrafluorethylene; however, other suitable materials may be used.

[00107] Referring to FIGURE 8, the interior of the rearward end bolt carrier bores is shown which may may have longitudinal grooves or flutes denoted 21 , 23 in

FIGURE 6 formed on the interior thereof to provide spaces for dirt and foreign material to collect without binding, to insure operation of the bolt when the firearm is subjected to wet or dirty environments. Alternatively, the unshown guide rods within the stock may be fluted instead of the inner surface of the bores to provide collector slots or grooves between the rods and the tubes.

[00108] In the present practice, in the illustrated exemplary embodiment the firearm has the sliding contact surfaces of the rods, bolt and bolt carrier including the bolt pin 208 and the surface of the bolt carrier slot 27 and the fluted surfaces 21 , 23 coated with a hardened coating having a surface hardness greater than 90 on the

Rockwell "C" scale and microfinished to a surface roughness of about 6 microinches.

[00109] Referring to FIGURE 7, the front view of the receiver is shown with the bores for receiving the tubes 24, 26 provided with fluted surfaces 45, 47 for providing space for collecting foreign material which would otherwise tend to restrict movement of the carrier 22.

[00110] The hardened microfinish surfaces of the sliding contact parts of the tubes

24, 26, bolt carrier 22 and the bolt thus provide improved sliding action with reduced friction and improved wear characteristics without the need of lubricant. Heretofore the use of lubricants has proven to be a source of sticking and jamming in service when the lubricant becomes contaminated with foreign material. [00111] Referring to FIGURE 24, in the illustrated exemplary embodiment, the extractor spring or the plural nested springs 214, 216, may be formed of three strands of spring wire in the coil which may be braided and formed of a metal such as S2 "water hardened" steel having an interior hardness of about 20 and an exterior hardness of about 60 on the Rockwell "C" scale. The spring wire is able to withstand temperatures of about 45O⁰F which can be reached during sustained firing. The same materials may also be employed for the return bounce springs in the tubes 24, 26. Alternatively, a nickel alloy material having the trade name Inconel®, a trademark of the International Nickel Company, Inc., may be employed. [00112] Referring to FIGURES 3 and 4, the receiver subassembly 40 is equipped with a manual slidable retractor handle 46 on the left hand side thereof; and, the stock is provided with a bolt catch release lever 80 to permit manual release of the bolt when the bolt remains in the retracted position following the firing of the last round in the magazine.

[00113] Referring to FIGURE 14, the bolt carrier is shown with trigger/firing mechanism 60 with portions of the hammer 61 shown in the cocked position in solid outline and which hammer 61 is rotatable, upon release for firing, about cross-pin 62 disposed in the mechanism housing 63. Upon release for firing, the hammer 61 moves to the position shown in dashed outline to strike the enlarged end 408 of the firing pin 402. The hammer 61 is moved to the cocked position by a cocking piece 63 provided on the rearward end of the bolt carrier 22, when the bolt is moved rearward to the position shown in dashed outline. In the exemplary embodiment shown, cocking piece 63 is formed of polyarylamide material about 50% glass fiber reinforced with a tensile strength of about 260 Mega Pascals and a tensile modulus of about 20 Giga Pascals.

[00114] Referring to FIGURES 4, 33 and 34, bolt catch release lever 80 has a pawl 97 attached which is operative to engage and lift bolt latch member 93 disposed for vertical sliding movement in the stock 16. Upon the user pushing on the upper end 79 of lever 80, pawl 97 on lever 80 engages cam surface 95 on latch member 93 and moves member 93 downwardly to engage the bolt carrier and hold the carrier in the retracted position. Movement of the lower end of lever 80 releases pawl 97 from surface 95, allowing member 93 to be raised by a spring (not shown) to release the bolt carrier.

[00115] The firearm of the present invention is also equipped with a forward assist button 82 shown in FIGURE 4 which upon user actuation secures forward positioning and locking of the bolt.

[00116] Referring to FIGURES 31 and 32, the forward assist button 82 is shown as attached to a piston or plunger 83 slidably supported in an external boss 81 provided on the stock 16 (see FIGURES 1 and 4). The piston has a pawl 85 provided on the end thereof which engages circumferential ratchet teeth-rings indicated generally at 87 in FIGURES 6 and 32 formed on the bolt carrier tube 26. It will be understood that piston 83 and pawl 85 are spring biased outwardly by a suitable spring (not shown) within boss 81. Thus, repeated pushing of button 32 strokes pawl 85 to advance the carrier tube 26, 24 and bolt carrier 22 in a forward direction to close the bolt silently as compared to pulling and releasing bolt carrier retractor handle 46 and letting the return springs close the bolt with resultant sound generated thereby.

[00117] A safety is provided on the left side of the weapon as shown at 84 in FIGURES 3 and 4; and, another safety is provided denoted 86 in FIGURE 2 on the right side of the firearm. Each safety is provided red markings thereon which, when visible, indicate the weapon is ready to fire and with white markings thereon, which, when visible, indicate that the weapon is in a safe mode. In the presently illustrated exemplary embodiment, the safety 84, 86 have markings on the forward and rearward surfaces such that they are visible from the front or rear of the weapon and from either side, thereby providing a readily visible quick reference indication to the user of the state of readiness of the weapon.

[00118] Referring to FIGURES 11 -14, the magazine 50 is illustrated with a case 52 formed of plastic or composite material; and, in the presently illustrated exemplary embodiment, Radel® 5000 available from Solvay of Pittsburgh, Pennsylvania or Amoco of Alpharetta, Georgia has been found satisfactory; however, other suitable materials may be employed having the mechanical properties of tensile strength of about 10.1 KPSI, tensile impact strength of about 190 Ft-16/in², deflection temperature of 405^g at 264 PSI (182MPa)₁ greater than 1000 cycles steam sterilization with Morpholine without cracking, crazing or rupture and mold shinkage of about 0.7%. The upper end of the magazine 50 has horizontal ribs 56, 58, 59 formed on the sides thereof for providing reinforcing of the magazine. [00119] Referring to FIGURE 13, a pair of oppositely disposed guide ribs or lugs 88, 90 are provided in the underside of the receiver 44 for guiding the engagement of the upper end of the magazine into the receiver; and, the lugs 88, 90 engage unshown grooves formed in the faces of the sides of the magazine such that only a magazine provided with these grooves will fit into the receiver of the firearm. Thus, although the firearm of the present disclosure may have interchangeable barrels chambered for various common available rounds or ammunition, if the weapon falls into the hands of unauthorized users, the weapon could only be fired by reloading the attached magazine in; as, no other existing magazines could be attached to the receiver.

[00120] Referring to FIGURES 2-5 and 15-19, a sighting structure indicated generally at 100 is found mounted on the firearm receiver 44; and, it will be apparent that the sighting structure also functions as a carrying handle for the firearm. The receiver 44 has a plurality of longitudinally spaced bosses 102, 104, 106, 108, 110 formed on the upper surface thereof and longitudinally spaced there along; and, the lower surface of the sighting structure has a plurality of longitudinally spaced correspondingly shaped recesses 112, 114, 116, 118, 120 formed thereon to permit direct attachment and positioning of the sighting structure on the receiver with precision alignment.

[00121] Each of the bosses 104, 106, 108 on the receiver has a threaded bore denoted respectively 122, 124, 126 formed therein. Each of the recesses 114, 116, 118 formed in the undersurface of the sighting structure communicates with bores or apertures 128, 130, 132 formed through the lower rail 134 of the sighting structure 100. Each of the bores 128, 130, 132 has a side bore denoted respectively 136, 138, 140 formed therein which extend outwardly to the sides of the rail 134. Each of the side bores 136, 138, 140 is adapted to have a ratchet plunger or pawl (not shown) disposed therein and spring biased inwardly with the spring and plunger or pawl retained by a suitable fastener threadedly engaging the bores 136, 138, 140. These latter have been omitted from the drawings for the sake of simplicity. [00122] Referring to FIGURES 17, 18 and 19, the sighting structure 100 is shown in place on the upper surface of the receiver with the bosses 102-110 engaging the recesses 112-120 and with retaining fasteners 142, received in the bores 128, 130, 132 and threadedly engaging the threaded bores 122, 124, 126 in the receiver. The fasteners 142 have a head 144 formed with a plurality of radially outwardly extending bores 146 formed thereon in circumferentially spaced relationship and with the shaft 150 of the fastener, which shaft extends from the undersurface of the head 144 formed with the lower end thereof provided with suitable threads 152 for engaging the threaded bores in the upper surface of the receiver. [00123] A plurality of ratchet teeth 154 are provided on the shaft 150 intermediate the threaded portion and the undersurface of the head, which ratchet teeth are respectively engaged by the unshown pawl or plungers provided in the cross bores 136, 138, 140 such that, upon tightening of the fastener in the threaded bores, reverse rotation is prevented by engagement of the ratchet teeth 154 with the pawls. [00124] The circumferentially spaced bores 146 provided in the outer periphery of the head 144 are sized and configured to be engaged by the smaller end of the cartridge case for the round of ammunition employed in the present firearm, as a tool employed by the user, for tightening the fasteners upon installation of the sighting structure.

[00125] Referring to FIGURE 19, the upper surface of the head 144 of the fastener has provided thereon a slot or recess 156 which is sized and configured to be engaged by the rim of the cartridge case for the round of ammunition employed in the firearm, such that in the event that a spent cartridge is not readily available at the time of installation, the cartridge rim may be used to tighten the fastener. Additionally, the upper surface of the fastener head 144 has a polygonal recess 158 formed therein to be engaged by a tool such as, for example, an Allen wrench if such is available.

[00126] Referring to FIGURES 3 and 4, the sight 190 includes three adjustment knobs indicated generally at 300 disposed about the periphery thereof with the upwardly extending knobs 300 each having protector or shield lugs 302 extending from the sight by about the same height as knobs 190 to protect the knobs from damage during usage.

[00127] Referring to FIGURES 39-41 , one of the knobs 300 is shown in detail as comprised of a lower retaining knob 304 for retaining the sight mechanism within the handle and which has a reduced diameter position 306 for threadedly engaging corresponding threads in the handle. Lower knob 193 has a stepped through-bore 308 which has rotably received therein a reduced diameter portion 310 of upper knob 312, which portion 310 has a circumferential groove 314 and an engagement surface, such as, for example, a slot 316 formed in the end thereof for engaging a corresponding member (not shown) within the sight for effecting adjustment thereof. Detents 318 are provided on the upper surface of knob 304 one of which is visible in FIGURE 40 for engaging corresponding detenting surfaces 324 on the undersurface of upper knob 312 to provide a ratcheting effect upon user rotation of knob 312 with respect to knob 304. A pair of locking screws 320 are threadedly engaged in internally threaded cross holes 322 and formed in the bore 308 in lower knob 304 for engaging groove 314 in the upper knob for retaining the knob in the adjusted position in lower knob 304.

[00128] Referring to FIGURES 27-30 an integral suppressor and barrel subassembly is shown generally at 240 which is suitable for use with a gas operated autoloading firearm such as for example, the firearm 10 shown in FIGURE 1. Subassembly 240 is intended as interchangeable with barrel 34 by virtue of the quick-connect threads 242 provided thereon, which are similar to threads 32, for connection to receiver 40. Barrel subassembly 240 is shown received through a bore 244 in a gas cylinder member 246 which is similar to cylinder 70 of the firearm of FIGURE 1. Gas cylinder member 246 has a gas operating chamber or bore 248 which is adapted to receive an operating piston (not shown) and has an opening 250 in the end of bore 248 for receiving the end of an operating tube/rod, such as the piston formed on end of tube 26, for being contacted by the unshown piston. Gas chamber bore 250 has an exhaust port 251 extending radially inwardly to the barrel bore 244; and, port 251 is located to communicate with an annular collector groove or recess 252, formed on the outer periphery of the barrel 254 and the communication is shown by the heavy black line in FIGURE 30. Barrel 254 also has a groove or recess 256 formed along the outer surface thereof with one end communicating with collector groove 252 and extending therefrom toward the muzzle end of the barrel.

[00129] Subassembly 240 includes a suppressor indicated generally at 260 having an outer tubular shell 262 sealingly attached as for example by weldment, to an end fitting 264 which is received over the muzzle end of barrel 254 and affixed thereto, as, for example, by weldment to form a one piece barrel and suppressor subassembly 240. Suppressor 260 includes an inner tubular shell member 266 disposed within outer shell 262; and, member 266 has the rearward end thereof or end distal the discharge end secured to the forward end of fitting 264 and forms a relatively narrow annular passage 268 between the outer surface of shell 266 and the inner surface of outer shell 262. End fitting 264 has a tortuous or baffled passage denoted by heavy black line through cross ports 270 and annular baffles 272 connecting groove 256 to passage 268 and discharging from the forward or muzzle end of suppressor 260.

[00130] The inner shell 266 has disposed therein a tubular support member with a plurality of annular baffles 274 disposed therein for baffling and suppressing the muzzle discharge blast from barrel 254. The subassembly 260 thus provides a one piece suppressor and barrel with internal venting of the gas from the operating piston chamber and is configured to be quickly interchangeable, as a unit with the basic barrel of a gas operated autoloading firearm and particularly the firearm configuration of FIGURE 1.

[00131] Referring to FIGURE 2, 3 and 5, a quick-release sling mounting boss and aperture 160 is provided in the front of the receiver 44 which aperture has a circumferential undercut groove 162 formed therein which serves as a detent or retaining surface upon insertion of a quick-release sling mounting fitting therein as will hereinafter be described.

[00132] Referring to FIGURES 20 and 21 , a quick-release sling mounting fitting is indicated generally at 170 and includes a cylindrical member 172 having a blind bore 174 formed therein with a pair of diametrically opposed outwardly extending bosses 176, 178 formed thereon which bosses have received therein respectively in boxes 180, 182 the ends of a shackle or wire loop or ring 184 which is adapted to have a sling or strap attached thereto.

[00133] The sides of the cylindrical member 172 have a plurality of tapered apertures 186 formed there through in circumferentially spaced arrangement with each of the apertures 186 having disposed therein a plunger 188 which may have a spherical configuration as illustrated in FIGURE 21. The bore 174 in the fitting member 172 has disposed therein a cylindrical plunger which has a tapered or groove formed thereon as indicated at 190; and, the cylindrical plunger 192 extends outwardly of the bore 174 and is biased in the outward direction by a spring 194 disposed in the bottom of the bore 174. The outward bias of the spring causes the taper 190 to register against the plungers 188 and by cam action force the plungers in an outward direction to extend outwardly of the member 172. [00134] The user installs the fitting member 170 in the bore 160 in the receiver by depressing the plunger 192 in the bore 174 so as to release the plungers 188 and permit them to move inwardly such that the cylindrical member 172 may be inserted in the bore 160 and upon release of the plunger the spring causes the surface 190 to bias the plungers 188 outwardly to engage the undercut groove 162 in the receiver and retain the sling fitting securely therein. The user may release the sling quickly by depressing the plunger 192 to release the small plungers 188 from the undercut 162 and the member 172 may then be removed easily from the bore 160. [00135] Referring to FIGURE 5, receiver 44 has a plurality of longitudinally spaced bosses 200, 202, 204 extending from one side thereof. The bosses each have bores therein which may have helical thread forming coils therein for receiving fasteners for accessory mounting.

[00136] Referring to FIGURES 35-38, stock 16 is shown with one half shell removed at its plane of symmetry and includes rear internal stiffening ribs 350, 352 oriented generally horizontally with voids or apertures 354, 356 respectively formed therein. Stock 16 also includes drain holes 358, 360 located in the lower wall of stock 16 positioned vertically below apertures 354, 356 for rapid water drainage upon removal from immersion.

[00137] Stock 16 has a forward stiffening rib 362 in the vicinity of the handle and trigger, with apertures 364 therein. A plurality of drain holes 366 are formed in the lower wall of the stock and positioned vertically below apertures 364 for rapid water drainage upon removal from immersion.

[00138] Referring to FIGURE 42, the firing pin assembly indicated generally at 400 includes a firing pin denoted 402 and a lock member 404 received over the firing pin. Lock member 404 has a cam surface 406 which, upon insertion of the firing pin into aperture 230 in the bolt 202 and in sections of the bolt assembly into bolt carrier 22 (see FIGURE 8) is rotatable to engage corresponding locking surfaces (not shown) in the bolt carrier 202. Firing pin 402 has an enlarged head 40 on the rearward end thereof which is engaged by hammer 410 (see FIGURE 14) for driving the reduced diameter forward end 412 into the percussive cap of the round to be fired. In the illustrated exemplary embodiment, the lock member is formed of about 50% glass fiber reinforced polyacrylamide material having a tensile strength of about 37 Kpsi (260 MPa) and an ISO 75A heat deflection temperature of about 320^QC (446^QF). [00139] Referring to FIGURES 10, 43 and 44, the gas operating cylinder member 70 is shown with bore 74 received over barrel 34 with a pair of downwardly extending laterally spaced flanges 430, 432, with cross holes 434, 436 respectively formed therein.

[00140] A forward grip 438 has a lug 440 extending upwardly therefrom which lug has a vertically extending slot 442 formed therein. A cross pin 444 has a circumferentially extending groove 446 formed adjacent an end thereof opposite an enlarged diameter head portion 448. Upon assembly, grip lug 440 is inserted between flanges 430, 432 and the slot 442 aligned with cross holes 434, 436 and pin 444 is inverted through cross hole 434, slot 442 and cross hole 436 with the groove 446 extending outwardly of cross hole 436. A "c" ring 450 is then engaged over groove 446 to retain the pin 444 in place and thus secure the grip 438 to the barrel. The slot 442 enables the grip 438 to be rotated about pin 444 and folded upwardly against the barrel when desired by the user. The "c" ring 450 is readily removable by the user, thus facilitating removal of grip 438 when disassembly is required. [00141] Referring to FIGURES 1 , 2 and 45-47, the stock 16 has a spent cartridge ejection port 19 on the right side thereof for right handed shooters and an ejection port 17 on the left side thereof for left handed shooters. In the exemplary embodiment illustrated, an ejection port cover 460 has a twist-locking hub formed on the underside thereof, with lugs 464, 466 which, upon insertion into one of the ports 17, 19, and upon a quarter turn in the clockwise direction, engage the sides of the respective slot 17, 19 and receive the member 460 over the desired port. Cover 460 may include warning indicia 470 thereon to warn the user to cover the port facing the user. The cover 460 is shown initially inserted in port 19 in FIGURE 45 and in the locked or engaged position in FIGURE 46.

[00142] Referring to FIGURE 5, in the exemplary embodiment illustrated, receiver 44 has a plurality of slots mounded along both sides thereof for air cooling, three of which are illustrated on the right side in FIGURE 5 and denoted 480, 482, 494. [00143] The exemplary embodiments have been described with reference to the drawings. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiments be construed as including all such modifications and alterations or equivalents thereof insofar as they come within the scope of the appended claims.

Claims

CLAIMS:

1. A firearm having a butt end and a muzzle end comprising:

a stock at said butt end of said firearm having a magazine opening adapted to receive a magazine of ammunition;

a receiver adjacent said stock;

a barrel having a bore, a barrel axis, a muzzle adjacent said firearm muzzle end and a receiver end, said receiver end being adjacent said receiver;

a chamber adapted to receive a round of ammunition;

a trigger longitudinally located between said magazine opening and said firearm muzzle end; and,

a sight mounting structure at the top of said receiver comprising alignment surfaces selected from the class of upstanding protrusions and recesses, and at least one bore adapted to receive a fastener from a selected sight.

2. The firearm of claim 1 , wherein said at least one bore has a threaded internal surface.

3. The firearm of claim 2, wherein said at least one bore is lined with a helical wire insert.

4. The firearm defined in claim 1 , wherein the barrel is readily user removable from the receiver for changing barrels.

5. The firearm defined in claim 1 , further comprising:

(a) a bolt moveably disposed on the receiver for loading and locking a live round into and retracting a spent cartridge from the chamber; and,

(b) a gas pressure operated member disposed for effecting unlocking and retracting movement of the bolt upon firing of a round, wherein the bolt and pressure operated member include unlubricated microfinished contacting surfaces.

6. The firearm defined in claim 5, wherein the bolt is moveably disposed in a bolt carrier slidably mounted with respect to the receiver and stock; and, the sliding surfaces thereof are coated unlubricated micro-finished surfaces having a surface hardness of at least 90 on the Rockwell "C" scale.

7. The firearm defined in claim 5, wherein the bolt is spring biased in a direction for loading, the spring being formed with three nested wire members.

8. The firearm defined in claim 7, wherein the spring has a coiled configuration.

9. The firearm defined in claim 5, wherein the receiver includes a pair of bores each with a rod disposed therein for relative movement there between during firing, wherein the surface of one of (a) the rod and (b) corresponding bore is fluted for permitting passage of foreign material.

10. The firearm defined in claim 1 , further comprising a sighting scope with adjustment markings using arrows and Roman numerals.

11. The firearm defined in claim 1 , wherein the receiver includes an accessory rail mounting including a plurality of bosses each with a recess formed therein for accepting one of said fasteners employed for said selected sight.

12. The firearm defined in claim 1 , wherein the receiver includes a sling mounting recess with undercut surfaces for engaging a quick-release sling fitting.

13. The firearm defined in claim 1 , wherein the bolt is moveably disposed in a bolt carrier slidably mounted on the stock; and, the receiver is configured for quick-change of the barrel without disassembly.

14. The firearm defined in claim 1 , wherein the bolt is moveably disposed in a carrier slidably mounted on rods disposed on the stock wherein the rods are formed of 316 stainless steel.

15. A firearm having a butt end and a muzzle end comprising:

a stock at said butt end of said firearm having a magazine opening adapted to receive a magazine of ammunition;

a receiver adjacent said stock;

a barrel having a bore, a barrel axis, a muzzle adjacent said firearm muzzle end and a receiver end, said receiver end being adjacent said receiver;

a chamber adapted to receive a round of ammunition;

a trigger longitudinally located between said magazine opening and said firearm muzzle end; and,

a sight mounting structure at the top of said receiver including alignment surfaces, and at least one bore adapted to receive a fastener from a selected sight whereby a sight may be mounted to said receiver without longitudinal sliding.

16. The firearm defined in claim 15, wherein said fastener includes a threaded shaft with ratchet teeth.

17. The firearm defined in claim 1 , wherein the receiver includes an accessory rail mounting including a plurality of bosses with a recess formed therein for accepting one of said fasteners employed for said selected sight.

18. A firearm having a butt end and a muzzle end comprising:

a stock at said butt end of said firearm having a magazine opening adapted to receive a magazine of ammunition;

a receiver adjacent said stock;

a barrel having a bore, a barrel axis, a muzzle adjacent said firearm muzzle end and a receiver end, said receiver end being adjacent said receiver;

a chamber adapted to receive a round of ammunition; a trigger longitudinally located between said magazine opening and said firearm muzzle end; and,

an accessory mount on a side of said receiver comprising at least one bore having a threaded internal surface.

19. The firearm of claim 18, wherein the bore is formed in a boss extending from the side of the receiver.

20. The firearm of claim 18, wherein said bore is lined with a helical wire insert.

21. The firearm of claim 18, wherein said accessory mount includes at least two bores in at least two bosses extending from the side of said receiver, and spaced longitudinally thereon.

22. The firearm of claim 18, wherein said firearm has a center of gravity and said accessory mount is adjacent said firearm center of gravity.

23. A firearm having a butt end at the rear of said firearm and a muzzle end at the front of said firearm comprising:

a barrel having a bore, a barrel axis, a muzzle adjacent said firearm muzzle end and a receiver end;

a stock at said butt end of said firearm having a magazine opening adapted to receive a magazine of ammunition and at least one rod having an axis generally parallel to said barrel axis and a uniform cross section over at least a portion of the length of the rod;

a receiver having a front end adjacent said barrel receiver end, and a rear end adjacent said stock and at least one receiver bore substantially parallel to said barrel axis;

a chamber adapted to receive a round of ammunition; a trigger longitudinally located between said magazine opening and said firearm muzzle end;

a bolt carrier assembly adjacent the rear end of said receiver having at least one tube substantially parallel to said barrel axis said tube having an generally uniform internal cross section over at least a portion of its length, said at least one tube surrounding a portion of said rod and slidable on said rod, said internal cross section provided with at least one longitudinal groove whereby at least one open passage between said rod and said tube is provided by said groove when said tube engages said rod.

24. The firearm of claim 23 wherein said at least one bolt carrier tube is slidably received in said at least one receiver bore and each said receiver bore has at least one longitudinal groove providing at least one open passage between said receiver bore and said tube when said tube engages said receiver bore.

25. The firearm defined in claim 23, wherein said carrier includes a bolt with an operating lever and bolt catch; and, the stock includes a bolt catch release lever separate from the operating lever.

26. The firearm defined in claim 23, wherein the bolt carrier includes a plurality of rollers operative for contacting the bolt.

27. The firearm defined in claim 26, wherein at least two of said rollers are spaced longitudinally on the bolt carrier.

28. The firearm defined in claim 23 further comprising a forward assist button operative for effecting quiet closing of the bolt.

29. A firearm having a butt end and a muzzle end comprising:

a stock at said butt end of said firearm having a magazine opening adapted to receive a magazine of ammunition;

a receiver adjacent said stock; a barrel having a bore, a barrel axis, a muzzle adjacent said firearm muzzle end and a receiver end, said receiver end being adjacent said receiver;

a chamber adapted to receive a round of ammunition;

a trigger longitudinally located between said magazine opening and said firearm muzzle end; and,

a safety actuator adapted to move transversely to said barrel axis having a safe position in which a portion of said safety actuator extends from one side of said firearm and a firing position in which said safety actuator extends from a second side of said firearm, said safety actuator being marked with a red indicator visible from the front, rear, top and bottom of said firearm when said safety actuator is in said firing position and a white indicator visible from the front, rear, top and bottom of said firearm when said safety actuator is in said safety position.

30. A firearm having a butt end and a muzzle end comprising:

a stock at said butt end of said firearm having a magazine opening adapted to receive a magazine of ammunition;

a receiver adjacent said stock;

a barrel having a bore, a barrel axis, a muzzle adjacent said firearm muzzle end and a receiver end, said receiver end being adjacent said receiver;

a chamber adapted to receive a round of ammunition;

a trigger adapted to fire said firearm when pulled, said trigger having a rest position, a single round fire position offering a first level of resistance and a second firing position past said single round firing position, said trigger being longitudinally located between said magazine opening and said firearm muzzle end; and,

an externally accessible firing selector switch having a first position and a second position, wherein upon the user pulling said trigger to said trigger second firing position causes said firearm to fire a burst of a selected number of rounds less than said magazine capacity, when said fire selector switch is in said first position, and upon the user pulling said trigger to said trigger second firing position causes said firearm to fire in fully automatic mode when said firing selector switch is in said first position.

31. A firearm having a butt end and a muzzle end comprising:

a stock at said butt end of said firearm having a magazine opening adapted to receive a magazine of ammunition, said magazine opening having an inwardly extending projection at a selected location;

a receiver adjacent said stock;

a barrel having a bore, a barrel axis, a muzzle adjacent said firearm muzzle end and a receiver end, said receiver end being adjacent said receiver;

a chamber adapted to receive a round of ammunition;

a trigger longitudinally located between said magazine opening and said firearm muzzle end; and,

a magazine adapted to hold and dispense a quantity of ammunition having a recess adapted to accommodate said stock projection and allow engagement of said magazine and said firearm.

32. The firearm of claim 31 , wherein said magazine has a polymeric outer wall and an open end adapted to dispense ammunition from said magazine and at least two polymeric lips adjacent said open end, said lips having reinforcing ribs extending toward said open end.

33. The firearm of claim 32, wherein said polymeric outer wall has peripheral ribs extending around said outer wall adjacent said open end, at least said topmost peripheral rib having an interruption forming said recess to accommodate said stock projection.

34. The firearm of claim 32, wherein said outer wall consists essentially of high performance polyamide.

35 The firearm of claim 32, wherein said outer wall consists essentially of amorphous thermoplastic polyetherimide (PEI).

36. A rotatable fastener for attaching a sighting device to a firearm adapted to fire a selected type of ammunition including a cartridge case, the fastener including a shaft and a head, said head having a plurality of holes spaced peripherally thereabout and sized to receive one end of said cartridge case as a tool for turning the fastener.

37. The fastener defined in claim 36, wherein the shaft includes ratchet teeth operable for resisting removal upon engaging in a plunger/pawl.

38. The fastener defined in claim 36, wherein the head includes a recess sized and configured to receive the rim of the cartridge case as a tool for the user effecting rotation of the fastener.

39. The fastener defined in claim 36, wherein the head includes a recess configured to receive a tool having a hexagonal shape for user effecting rotation of the fastener.

40. The fastener defined in claim 36, wherein the head has a portion thereof provided with a plurality of wrench flats.

41. The fastener defined in claim 36, wherein the head has a portion thereof formed in a hexagonal shape for engagement by a wrench.

42. The fastener defined in claim 36, wherein the shaft includes a threaded portion and a ratchet portion intermed into the head and the threaded portion.

43. The fastener defined in claim 42, wherein the ratchet teeth are undercut from the threaded portion.

44. A firearm having a butt end and a muzzle end comprising:

a stock at said butt end of said firearm having a magazine opening adapted to receive a magazine of ammunition;

a receiver adjacent said stock;

a barrel having a bore, a barrel axis, a muzzle adjacent said firearm muzzle end and a receiver end, said receiver end being adjacent said receiver;

a chamber adapted to receive a round of ammunition;

a trigger longitudinally located between said magazine opening and said muzzle end;

a removable sight structure, including at least one fastener threadedly engaging the receiver, wherein said at least one fastener includes surfaces engageable for turning by one end of a cartridge case for a round of ammunition as a tool.

45. The firearm defined in claim 44, wherein said fasteners are operable for adjustment of the sight.

46. The firearm defined in claim 44, wherein said fasteners have a plurality of radially extending bores.

47. The firearm defined in claim 44, wherein at least one of the fasteners includes a tapered shank contacting a tapered bore in the receiver.

48. The firearm defined in claim 47, wherein said fastener includes a ratchet mechanism.

49. The firearm defined in claim 44, wherein said fastener has an enlarged head with a slot across the top of the head having a configuration accommodating the base rim of the cartridge for a round of ammunition as a tool for turning.

50. A firearm having a butt end at the rear thereof and a muzzle end at the front thereof comprising:

(a) a barrel having a bore, a barrel axis, a muzzle adjacent the muzzle end and a receiver end;

(b) a stock at the butt end of the firearm having a magazine opening adapted to receive a magazine of ammunition and at least one rod having an axis generally parallel to the barrel axis;

(c) a receiver having a front end adjacent the barrel receiver end, and a rear end adjacent the stock and at least one receiver bore substantially parallel to said barrel axis;

(d) a chamber adapted to receive a round of ammunition;

(e) a trigger longitudinally located between the magazine opening and the firearm muzzle end;

(f) a trigger carrier assembly disposed adjacent the rear end of the receiver, having a locking bolt therewith operable for locking a round in the chamber; and,

(g) a quickly releasable sling.

51. A cartridge chambering bolt assembly for an autoloading firearm comprising:

(a) a bolt member having a distal end and a proximal end for contacting the cartridge to be chambered for firing;

(b) the bolt member including guide surfaces for guiding movement thereof;

(c) an extractor carried with the bolt member for engaging the rim of the cartridge case of a chambered cartridge; (d) a recess formed in the proximal end of the bolt member for receiving the end of the cartridge to be chambered, wherein the end of the bolt around the recess includes an inclined surface for guiding the cartridge case into the recess; and,

(e) a bore formed through the bolt member adapted for receiving a firing pin.

52. The bolt assembly defined in claim 51 , wherein the end of the bolt around the recess is inclined about 5^s.

53. The bolt assembly defined in claim 51 , wherein the extractor is spring biased.

54. The bolt assembly defined in claim 53, wherein the extractor is biased with plural nested coil springs.

55. The bolt assembly defined in claim 51 , wherein the bolt member includes an ejector.

56. The bolt assembly defined in claim 55, wherein the ejector is spring biased with material resistant to temperatures up to 800^sF (426^SC).

57. The bolt assembly defined in claim 56, wherein the ejector is formed of precipitation hardened stainless steel.

58. The bolt assembly defined in claim 55, wherein the ejector is formed of 17-7 type precipitation hardened stainless steel.

59. The bolt assembly defined in claim 55, wherein the ejector includes a pin hardened to about 52-56 on the Rockwell "C" scale.

60. The bolt assembly defined in claim 59, wherein the pin is hard Chromium plated.

61. The bolt assembly defined in claim 59, wherein the pin is hard Chromium plated by about 0.0005 in (0.013 mm).

62. The bolt assembly defined in claim 51 , wherein the bolt member includes a cam pin formed of a steel alloy having Chromium, Manganese and Molybdenum with a yield strength of about 220 Ksi (1518KPa).

63. The bolt assembly defined in claim 62, wherein the cam pin includes a flash hard chromium plating.

64. The bolt assembly defined in claim 51 , wherein the cartridge receiving recess has a tapered cylindrical wall.

65. The bolt assembly defined in claim 51 , wherein the extractor includes a seal formed of copolymers of one of tetrafluorethylene/polypropylene and ethylene/ perfluoromethyl vinylether/tetrafluorethylene.

66. The bolt assembly defined in claim 51 , wherein the inclined surface is inclined at an angle of about 5^Q.

67. The bolt assembly defined in claim 51 , wherein the proximal end of the bolt is formed of steel alloy having Chromium, Manganese and Molybdenum with a yield strength of about 220 Ksi (1518 MPa) and a hardness of about 52 on the Rockwell "C" scale.

68. The bolt assembly defined in claim 51 , further comprising a firing pin lock member formed of glass fiber reinforced polyacrylamide material having a tensile strength of about 37 Kpsi (260 MPa) and an ISO 75A heat deflection temperature of about 230^sC (446^SF).

69. The bolt assembly defined in claim 68, wherein the lock member is formed of polyacrylamide material reinforced with about 50% glass fiber.

70. A receiver and detachable barrel assembly for an autoloading firearm comprising: (a) a receiver adapted for attachment to a stock and having an opening for receiving an end of a barrel and a plurality of flow passages therethrough;

(b) a barrel having a chambered end and a discharge end, with engagement surfaces thereon proximate the chambered end and said engagement surfaces releasably engaging corresponding surfaces formed in the receiver opening for retaining the barrel on the receiver; and,

(c) the barrel including longitudinally extending channels thereon communicating with the receiver flow passages thereby enabling cooling airflow along the barrel through the channels and outwardly through the flow passages.

71. The assembly defined in claim 70, wherein the channels are formed by fluting on the barrel.

72. The assembly defined in claim 70, wherein the receiver is formed of material having a relatively high coefficient of thermal conductivity and serves as a heat sink for the barrel.

73. The assembly defined in claim 70 wherein the receiver is formed of investment cast aluminum alloy.

74. The assembly defined in claim 73, wherein the receiver is formed of investment cast aluminum silicon alloy.

75. A gun stock, barrel and receiver assembly for an autoloading firearm comprising:

(a) a gun stock having a barrel receiver mounted thereon and a pair of spaced generally parallel bolt carrier tubes thereon;

(b) a bolt carrier slidably received on the tubes;

(c) the tubes having portions thereof engaging the receiver;

(d) said tubes having a plurality of apertures formed through the wall thereof; and,

(e) a plurality of channels in the stock communicating with the apertures for effecting rapid water drainage upon retrieval from water immersion.

76. An integral sound suppressor and barrel assembly for an autoloading firearm comprising:

(a) a barrel having a cartridge chambered end and a discharge end and a gas operated piston chamber disposed intermediate the ends thereof and a passage communicating the piston chamber with the bore of the barrel;

(b) a sound suppressor formed as one piece with the discharge end of the barrel and having a first chamber communicating with the discharge end of the barrel and a second chamber communicating through an exhaust passage with said piston receiving chamber; and,

(c) a piston received in the piston chamber and adapted for, upon attachment of the barrel assembly to the firearms, contacting a bolt operating rod, wherein the assembly is adapted for quick removal and attachment to the firearm as a unit.

77. The assembly defined in claim 76, wherein the first chamber has an annular configuration.

78. The assembly defined in claim 76, wherein the second chamber annularly surrounds the chamber.

79. The assembly defined in claim 76, wherein the exhaust passage is sized to prevent pressure buildup in the piston chamber greater than the pressure buildup in the chamber with a barrel operated without a sound suppressor.

80. The assembly defined in claim 79, wherein the exhaust passage has a minimum cross-section of about 80% of that of the piston chamber exhaust passage of a barrel operated without a sound suppressor.

81. An autoloading firearm comprising:

(a) a stock with a butt end and a forward end;

(b) a receiver mounted proximate to the forward end of the stock;

(c) a removable magazine mounted proximate the butt end of the stock;

(d) a firing trigger mounted forward of magazine;

(e) a user handle/grip forward of the trigger;

(f) a barrel received in the forward end of the receiver and retained therein for quick release and interchange thereof; and,

(g) a removable bolt assembly moveably disposed on the stock for chambering and locking a cartridge for firing.

82. The firearm defined in claim 81 , wherein the weapon is quickly convertible for firing a different caliber round by interchanging only the barrel, bolt assembly and magazine.

83. The firearm defined in claim 81 , wherein the bolt assembly includes an extractor and an ejector.

84. The firearm defined in claim 81 , wherein the magazine is molded of polyphenylsulfone material.

85. A method of making an integral barrel and suppressor for an autoloading firearm comprising:

(a) forming a barrel with a chambered end and a discharge end;

(b) forming an operating piston chamber intermediate the chambered end and the discharge end and communicating the piston chamber with the bore through an inlet passage and disposing an operating piston in the chamber; (c) forming a suppressor about the discharge end of the barrel and forming a first chamber in the suppressor and communicating the first chamber with the discharge end of the bore;

(d) forming an exhaust passage in the piston chamber and forming a second chamber in the suppressor and communicating the exhaust passage with the second chamber.

86. The method defined in claim 85, wherein the step of forming a piston chamber includes forming a housing integrally with the barrel adjacent the bore.

87. The method defined in claim 85, wherein the step of forming a suppressor includes welding a tubular member to the discharge end of the barrel.

88. The method defined in claim 85, wherein the step of forming a barrel includes forming quick disconnect/attachment surfaces on the chambered end adapted for attaching the barrel to a receiver.

89. The method defined in claim 85, wherein the step of forming a first chamber includes forming an annular chamber.

90. The method defined in claim 85, wherein the step of forming a second passage chamber includes forming an annular chamber.

91. The method defined in claim 85, wherein the step of forming a second chamber includes forming an annular chamber surrounding the first chamber.