Reliability of a multi-lug breech bolt is improved by modifying the bearing relationship between the bolt lugs and the matching lugs within a gun receiver. This procedure is applied to a gun that has a receiver housing a breech bolt and an extractor. The extractor is coupled to the breech bolt and configured to move relative thereto. The bolt for this gun has at least five radially extending bolt lugs configured for bearing contact with the receiver when positioned for firing. The bolt lugs include a first, second, and third bolt lug with the first and second bolt lugs being adjacent and defining a gap configured to receive the extractor therebetween. The third bolt lug extends from the bolt opposite the gap. Stress imparted to the first and second bolt lugs from firing the gun is reduced by altering the gun to prevent formation of a bearing relationship between the third bolt lug and the receiver when the bolt lugs are positioned for firing. The gun is reassembled as part of the procedure. The alteration may be accomplished by removing material from the third lug, a corresponding lug of the receiver, or both.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of co-pending U.S. patent application Ser. No. 08/735,077, now filed Oct. 18, 1996 U.S. Pat. No. 5,911,173.
A bolt locking housing (16) on a gun, behind the chamber (4) thereof, for receiving a bolt (6) including an extractor (10) having an extractor hook that grips a corresponding extractor groove (21) of a cartridge (2) within said chamber (4), characterized by said bolt locking housing (16) being asymmetrically machined internally, such that there is provided at least a first protrusion (18) that becomes co-aligned with and serves to support head of extractor (10), when bolt (6) is fully closed and lugs (7) thereon are interlocked into bolt locking housing (16), thereby preventing deformation of casing of said cartridge (2) after detonation.
Existing floating handguards have the problem of adding size and weight to M16 style gas operated rifles because these tubular handguards attach to a relatively large diametral surface which lies outward of a firearm operating member or gas tube. Existing handguards are mounted thus so that the handguard inside surface will mechanically clear the gas tube. The present invention solves this problem by providing a handguard system integrated to a firearm, the system having a one-piece extended barrel nut with a smaller diameter outer surface configured to lie inward of the gas tube, between the gas tube and the barrel. A one-piece generally tubular handguard has an outer surface with a longitudinal rib and an inner surface with an inner diameter and a groove which is aligned with the rib. The handguard inner diameter engages the barrel nut outer surface and the groove provides clearance for the gas tube. The rib is configured to maintain the rigidity of the handguard adjacent the groove.
The bolt assembly includes a bolt head having a locked position and an unlocked position. The bolt head also has a periphery and an even number of arrangement sites located on the periphery. The bolt assembly further includes a plurality of locking projections positioned at a subset of the arrangement sites on the periphery of the bolt head. It also includes a cartridge extractor disposed at one of the arrangement sites which is not part of the subset and which is located horizontally adjacent the central longitudinal axis of the barrel when the bolt head is in the unlocked position.
A bolt assembly for use in a firearm is disclosed which is movably arranged in a weapon housing and which includes a bolt carrier and a bolt head. The bolt head can be alternately inserted in at least two positions in the weapon housing to adapt the firearm to eject spent cartridge casings in a desired direction. The bolt assembly also includes an extractor which is fastened laterally on the bolt or bolt head for withdrawing a cartridge casing from a barrel of the weapon housing during return of the bolt assembly, and an ejector integrated in the bolt mechanism which removes the cartridge casing from the bolt assembly after extraction from the barrel.
A rotatable breech gun including a breech assembly, a breech housing, and a gun barrel. The breech assembly has a breech bore formed therein that receives ammunition loaded through an end thereof. The breech housing has at least one side member oriented parallel to the breech bore. The breech assembly is rotatably mounted in the breech housing. The gun barrel has a gun bore extending therethrough. The gun barrel is operably connected to the breech housing such that the gun bore is aligned with the breech bore when the breech assembly is rotated in position within the breech housing. The breech assembly and the breech housing further include corresponding mating structures proximate at least one end of the breech bore such that forces generated by ignition of ammunition in the breech bore are transmitted to both the breech assembly and the at least one side member of the breech housing.
