Tactical rifle

Abstract

A tactical combat rifle includes a two-part, bolt carrier. The upper part of the bolt carrier rides on rails formed in an upper receiver while the lower part of the bolt carrier, although attached to the upper part and moving with it, engages no supporting surfaces. A piston, driven by combustion gases from a regulatable gas block assembly, strikes the upper bolt carrier in the center of its mass to propel it rearward. The barrel is threaded to a removable barrel extension and secured to the upper receiver. A non-reciprocating charging handle is located far forward and accessible from either side of the upper receiver so the user does not have to lower the rifle from the shoulder or take eyes off the target. Combustion debris is kept away from the lower receiver and bolt so operation is cleaner and cycling rates of fire steadier.

What is claimed is: 
     
         1 . A rifle, comprising:
 a barrel having a distal end and a proximal end and a chamber formed in said proximal end and a bore formed from said chamber to said distal end of said barrel and a hole formed in said bore of said barrel,   a gas block assembly attached to said barrel, said gas block assembly having an interior in communication with said hole in said bore of said barrel;   a piston slidably carried by said gas block assembly, said piston movable between a proximal position and a distal position so that gas from said barrel travels through said hole in said barrel to said interior of said gas block assembly and drives said piston from said distal position to said proximal position;   an upper receiver having rails, said barrel being housed in said upper receiver;   an upper bolt carrier slidable on said rails of said upper receiver and in operating connection with said piston of said gas block assembly so that when said piston slides proximally and strikes said upper bolt carrier, said upper bolt carrier slides proximally in response thereto;   a lower bolt carrier supported by and slidable with said upper bolt carrier;   a bolt carried by said lower bolt carrier;   a firing pin carried by said bolt;   a lower receiver attached to said upper receiver and having
 a trigger, and 
 a magazine well proximate to said trigger and dimensioned for receiving an ammunition magazine; and 
   a butt stock attached to said lower receiver.   
     
     
         2 . The rifle as recited in  claim 1 , further comprising a barrel extension attached to said proximal end of said barrel, said barrel extension holding said proximal end of said barrel to said receiver. 
     
     
         3 . The rifle as recited in  claim 1 , further comprising a regulator attached to said gas block having an adjustable vent with at least two positions, a first position wherein relatively more back pressure is delivered to said piston and a second position wherein relatively less back pressure is delivered to said piston. 
     
     
         4 . The rifle as recited in  claim 1 , wherein said upper bolt carrier and said lower bolt carrier are fastened together. 
     
     
         5 . The rifle as recited in  claim 1 , wherein said receiver has a charging handle operable from either side of said upper receiver. 
     
     
         6 . The rifle as recited in  claim 1 , wherein said bolt rotates as it moves from its distal position to its proximal position and wherein said bolt rotates to unlock from said chamber after said pressure in said chamber has decreased. 
     
     
         7 . A rifle, comprising:
 a barrel having a distal end and a proximal end and a chamber formed in said proximal end and a bore formed from said chamber to said distal end of said barrel and a hole formed in said bore of said barrel, said proximal end of said barrel having a threaded exterior;   a barrel extension having a threaded interior dimensioned for receiving said proximal end of said barrel, said barrel extension having plural lugs;   a gas block assembly attached to said distal end of said barrel, said gas block assembly having an interior in communication with said hole in said bore of said barrel;   a piston slidably carried by said gas block assembly, said piston movable between a proximal position and a distal position so that gas from said barrel travels through said hole in said barrel to said interior of said gas block assembly and drives said piston from said distal position to said proximal position;   an upper receiver having first rails and second rails, said barrel being housed in said upper receiver, said lugs of said barrel extension being supported on said second rails of said upper receiver;   an upper bolt carrier slidable on said first rails of said upper receiver and in operating connection with said piston of said gas block assembly so that when said piston slides proximally on said first rails and strikes said upper bolt carrier, said upper bolt carrier slides proximally in response thereto;   a lower bolt carrier supported by and slidable with said upper bolt carrier;   a bolt carried by said lower bolt carrier;   a firing pin carried by said bolt;   a lower receiver attached to said upper receiver and having
 a trigger, and 
 a magazine well proximate to said trigger and dimensioned for receiving an ammunition magazine; and 
   a butt stock attached to said lower receiver.   
     
     
         8 . The rifle of  claim 7 , wherein said barrel extension has two holes formed therein and where said barrel is pulled rearward against said receiver when said two screws are inserted and tightened in said two holes. 
     
     
         9 . The rifle of  claim 7 , wherein said upper receiver has a proximal end and a distal end, and wherein said rifle further comprises a charging handle carried by said distal end of said upper receiver. 
     
     
         10 . The rifle of  claim 9 , wherein said charging handle is non-reciprocating. 
     
     
         11 . The rifle of  claim 7 , wherein said bolt carries an extractor, said extractor being fastened to said bolt with a threaded pin. 
     
     
         12 . The rifle of  claim 7 , wherein said bolt has a recess and a pair of opposing holes on opposing sides of said recess, and wherein said bolt includes an extractor dimensioned to be receivable in said recess, said extractor having a hole formed therein, and wherein said hole in said extractor and said opposing holes are threaded, and wherein said bolt includes a threaded pin in said opposing holes and said hole in said extractor. 
     
     
         13 . The rifle as recited in  claim 7 , wherein said upper receiver further comprises a shell ejection port and wherein said rifle further comprises a shell deflector fastened to said upper receiver adjacent to said ejection port so that ejected shells are deflected by said shell deflector. 
     
     
         14 . The rifle as recited in  claim 7 , wherein said gas block assembly further comprises a regulator having plural user-selectable positions, a position of said plural positions providing a different back pressure to said gas block assembly so that back pressure on said piston may be altered. 
     
     
         15 . The rifle as recited in  claim 7 , wherein said upper receiver has a proximal end and a distal end, and wherein said upper receiver has a slot formed in said distal end and wherein said rifle further comprises:
 a charging sled carried within said receiver on said first rails;   a charging handle attached to said charging sled and extending from within said upper receiver through said slot, said charging handle configured for a user to pull said charging sled between said proximal position and said distal position; and   a hook pivotally mounted to said charging sled and pivoting between a hooked position and an unhooked position, said hook being in said hooked position to pull said upper bolt carrier to said distal position after charging said rifle and being in said unhooked position when said rifle is operating in said firing cycle.   
     
     
         16 . The rifle as recited in  claim 15 , wherein said upper receiver carries a spring biasing said hook in said unhooked position, when said charging sled is in said distal position. 
     
     
         17 . The rifle of  claim 7 , wherein said bolt further comprises a cam pin and upper receiver has a cam path formed therein, said cam pin extending through said bolt and into said cam path, said cam pin following said cam path as said upper bolt carrier and lower bolt carrier move from a distal position to a proximal position and back to a distal position in a firing cycle, said cam path configured so that said bolt is not unlocked from said chamber until pressure in said chamber is reduced. 
     
     
         18 . The rifle of  claim 7 , wherein said upper bolt carrier is brazed to said lower bolt carrier. 
     
     
         19 . The rifle of  claim 7 , wherein said upper bolt carrier has a closed passage formed therein said passage containing a powder freely movable within said passage. 
     
     
         20 . The rifle of  claim 7 , wherein said piston strikes said upper bolt carrier in the center of mass of said upper bolt carrier.