WO2008137187A2

WO2008137187A2 - Semi-automatic and automatic firearm

Info

Publication number: WO2008137187A2
Application number: PCT/US2008/050755
Authority: WO
Inventors: Anthony L. Marfione
Original assignee: Microtech Small Arms Research, Inc.
Priority date: 2007-01-10
Filing date: 2008-01-10
Publication date: 2008-11-13
Also published as: WO2008137187A3

Abstract

A compact firearm of the bull pup configuration, capable of operating in the semi-automatic, burst, and full automatic modes with an improved structure for mounting a sight or sighting device using 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.

Description

SEMI-AUTOMATIC AND AUTOMATIC FIREARM

FIELD OF THE DISCLOSURE

[0001] The present disclosure relates to a firearm with a rearwardly sliding breechblock and more particularly to a firearm of a type usable by the military.

BACKGROUND

[0002] 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.

[0003] One weapon used by various military organizations is the M-16 rifle. The M- 16 is gas operated 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.

[0004] Another design for firearms which can operate in either the semi-automatic 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. [0005] 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.

[0006] 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. [0007] 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.

[0008] 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. [0009] 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.

[0010] 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.

SUMMARY

[0011] In accordance with the present disclosure, a compact firearm of the bull pup configuration, capable of operating in the semi-automatic, burst, and full automatic modes is described.

[0012] 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. [0013] 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. [0014] 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.

[0015] 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.

[0016] 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. [0017] 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. [0018] 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.

[0019] 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.

[0020] 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. [0021] 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.

[0022] Yet further in accordance with the disclosure, a forward assist button is provided on the firearm forward of the front surface of the bolt.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] This disclosure describes a firearm with a sight or setting device which can be mounted on the firearm without sliding.

[0028] 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.

[0029] A firearm is described herein which can use ammunition only in magazines designed for the firearm.

[0030] The present disclosure describes a firearm which can be easily switched from full automatic to burst mode without disassembling the firearm.

[0031] 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. [0032] 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.

[0033] A firearm is described herein having a quickly removable sling.

[0034] 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.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIGURE 1 is an exploded view of the firearm of the present disclosure;

[0036] FIGURE 2 is a view from the right front of the assembled firearm of the present disclosure;

[0037] FIGURE 3 is a view of the assembled firearm of the present disclosure from the left front;

[0038] FIGURE 4 is a partial view of the assembled firearm of the present disclosure taken from the left rear;

[0039] FIGURE 5 is an enlarged view of the receiver of the present firearm;

[0040] FIGURE 6 is an enlarged view of the gun lock subassembly of the present firearm;

[0041] FIGURE 7 is a rear view of the receiver of FIGURE 5;

[0042] FIGURE 8 is a view of the bolt carrier of the firearm of FIGURE 1 ;

[0043] FIGURE 9 is a rear view of the gas cylinder member of the present firearm;

[0044] FIGURE 10 is a front view of the gas cylinder of FIGURE 9;

[0045] FIGURE 11 is a side view of the magazine for the firearm of FIGURE 1 ;

[0046] FIGURE 12 is a partial view of the magazine of FIGURE 11 showing the engagement surfaces;

[0047] FIGURE 13 is an under view of the magazine receptacle of the stock of the firearm of FIGURE 1 ;

[0048] FIGURE 14 is another view of the magazine receptacle showing engagement lugs;

[0049] FIGURE 15 is a view showing the attachment of the sighting structure to the magazine taken from below the sighting structure; [0050] FIGURE 16 is a view similar to FIGURE 15 taken from above the receiver and the sighting structure;

[0051] FIGURE 17 is a view showing the sighting structure attached to the receiver;

[0052] FIGURE 18 is a side view of the fastener employed in the attachment of

FIGURE 17;

[0053] FIGURE 19 is a view of the fastener of FIGURE 18 taken from above the fastener head;

[0054] FIGURE 20 is view of the sling attachment fitting;

[0055] FIGURE 21 is a section view taken along section indicating line A-A of

FIGURE 20; and,

[0056] FIGURE 22 is a section view taken along section indicating line B-B of

FIGURE 5.

DETAILED DESCRIPTION

[0057] 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. [0058] 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. [0059] 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. [0060] The magazine assembly is then inserted into the stock for engaging attachment surfaces in the receiver therein as will hereinafter described in detail. [0061] 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. [0062] 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.

[0063] 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 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. 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. [0064] 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 a lug (not shown) extending vertically upwardly from the bolt which it will be understood is captured within the bolt carrier 22 but not illustrated. The bolt carrier 22 has a pair of spaced rollers 29 disposed adjacent the ends thereof and positioned to contact the unshown bolt and provide guidance for the longitudinal movement of the bolt. [0065] The interior of the tubes 24, 26 may have longitudinal grooves or flutes denoted 24a, 26a in FIGURE 6 formed on the interior thereof to provide collector spaces for dirt and foreign material to insure operation of the bolt when the firearm is subjected to wet or dirty environments. Alternatively, the unshown rods within the stock may be fluted instead of the inner surface of the tubes 24, 26 to provide collector slots or grooves between the rods and the tubes.

[0066] In the present practice, the firearm has the sliding contact surfaces of the rods, bolt and bolt carrier including the unshown bolt lug and the surface of the bolt carrier slot 27 and the fluted surfaces 26A, 24A 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.

[0067] Referring to FIGURE 7, the front view of the receiver is shown with the tubes

26, 24 received therein and the barrel 34 in position.

[0068] The hardened microf inish surface of the sliding contact parts of the tubes 24,

26, bolt carrier 22 and the unshown bolt thus provides 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 contaminated with foreign material.

[0069] In the present practice, the extractor spring is formed of three strands of spring wire in the coil which may be braided and is 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 sustained firing resulting in temperatures of about 45O⁰F. 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™ may be employed.

[0070] 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. 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.

[0071] 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 with 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 present practice, the safety 84, 86 have marking on the forward and rearward surfaces such that they are visible from the front or rear of the weapon from either side thereby providing a readily visible quick reference indication to the user of the state of readiness of the weapon.

[0072] Referring to FIGURES 11-14, the magazine 50 is illustrated; with a case 52 formed of plastic or composite material; and, in the present practice, Radel® 5000 available from Solvay of Pittsburgh, Pennsylvania or Amoco of Alpharetta, Georgia. The upper end of the magazine 50 has horizontal ribs 56, 58, 59 formed on the sides thereof for providing reinforcing of the magazine.

[0073] Referring to FIGURES 13 and 14, a pair of oppositely disposed guide ribs or lugs 88, 90 are provided in the underside of the receiver 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 inner 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 much as no other existing magazines could be attached to the receiver.

[0074] 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. [0075] 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 1 14, 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.

[0076] 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.

[0077] 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. [0078] 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. [0079] 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. [0080] 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.

[0081] 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.

[0082] 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.

[0083] 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. [0084] 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.

[0085] The exemplary embodiment has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

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 receiver adjacent said stock;

a chamber adapted to receive a round of ammunition;

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 receiver adjacent said stock;

a chamber adapted to receive a round of ammunition;

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 receiver adjacent said stock;

a chamber adapted to receive a round of ammunition;

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 receiver adjacent said stock;

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 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 receiver adjacent said stock;

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.