AR Platform Firearm

Abstract

An improved AR platform firearm includes modular brass deflectors and brass catches; sleeved takedown and pivot pinholes; a cam latch device for a secure upper/lower receiver connection; a two-piece upper receiver; a taper-fit barrel system; a barrel alignment system using a barrel alignment washer; a charging handle that positively engages with the bolt carrier; a charging handle retention system using a spring detent; a bolt carrier with rear wall to absorb shear force on the gas key or anvil; a leak-proof gas system using a straight gas tube, ferrule and threaded connection with the gas block; a gas block stop notch that mates with a gas block key; a gas block jam nut for holding the gas block in place; an interchangeable gas system; an expansion chamber; a handguard with adjustable weights; a handguard lock-up mechanism; a handguard extender; and a sloped Picatinny rail for extending scope utilization.

I claim: 
     
         1 . An AR platform firearm, comprising an upper receiver and a lower receiver, wherein:
 the upper receiver has a pinhole configured to receive a takedown pin, and a pinhole configured to receive a pivot pin;   the lower receiver has one or more pinholes configured to receive a takedown pin, and one or more pinholes configured to receive a pivot pin; and   wherein one or more of said pinholes comprise a tubular sleeve, which is configured to fit into said one or more pinholes, and to receive a said takedown pin or pivot pin.   
     
     
         2 . A modular brass deflection system for use with an AR platform firearm, comprising:
 a hole drilled into an ejection side of an upper receiver with an ejection port; and   a deflection component having a hole, a connector portion, a deflector portion, a receiver-side edge with a shape, and a bottom surface of the deflector portion with a shape and back and front ends;   wherein said bottom surface shape is profiled for an ejection direction; and   wherein said receiver-side-edge shape hugs a portion of the ejection side of the upper receiver located behind and above the ejection port.   
     
     
         3 . A modular brass catch system for use with an AR platform firearm, comprising:
 a hole drilled into an ejection side of an AR platform upper receiver with an ejection port; and   a fastener component having a hole, a connector portion, an adaptor portion, a receiver side edge with a shape, and a bottom surface of the adaptor portion with a shape and back and front ends;   wherein said adaptor portion is configured to hold a collection component for spent cartridges; and   wherein said bottom surface shape is profiled to direct spent cartridges in a collection direction; and   wherein said receiver-side-edge shape hugs a portion of the ejection side of the upper receiver located behind, above and in front of the ejection port.   
     
     
         4 . A receiver locking system for use with an AR platform firearm, comprising:
 a lower receiver having one or more takedown pinholes, a non-ejection side and a cam lever device mounted in the takedown pinhole, on the non-ejection side; and   an upper receiver having a buffer end, a barrel end, a takedown pinhole location, and a non-ejection side with a rail extending from a point above the takedown pinhole location, forward and downward to a lower point which is above and in front of the takedown pinhole location;   wherein said cam lever device comprises a mounting structure, a latch and a cam lever; and   wherein said latch is configured to catch onto said rail; and   wherein said cam lever is configured to adjust an axial position of the latch in relation to the mounting structure.   
     
     
         5 . An AR platform two-piece upper receiver, comprising:
 an upper receiver with a pocket with a threaded inner surface; and   a tubular insert with a threaded outer surface;   wherein the insert is threadedly installed into the upper receiver pocket, forming a snout.   
     
     
         6 . A taper fit barrel system for use with an AR platform firearm, comprising:
 an upper receiver with a snout having a tapered inner receiving surface; and   a barrel with a breech end having a tapered outer surface which mates with the upper receiver snout's inner receiving surface.   
     
     
         7 . A taper fit barrel system, comprising the two-piece upper receiver of  claim 5 , and
 a barrel with a breech end having a tapered outer surface;   wherein the tubular insert further comprises a tapered inner receiving surface which mates with the barrel's tapered outer surface.   
     
     
         8 . A barrel alignment system for use with an AR platform firearm, comprising:
 a barrel having a breech end, a flange, an outer surface and an alignment pin protruding from the outer surface, between the breech end and the flange;   an upper receiver snout having a tapered rectangular notch; and   a removable alignment washer having a tapered rectangular shape and size configured to fit into the notch, and having a central hole configured to receive the alignment pin.   
     
     
         9 . An AR platform charging handle/bolt carrier assembly, comprising:
 a charging handle with a handle and a distal end; and   a bolt carrier having a receiving location configured to receive the distal end of the charging handle;   wherein the distal end of the charging handle has an undercut, forming a hooked shape; and   wherein the bolt carrier's receiving location has a corresponding undercut configured to mate with the charging handle's distal end's shape.   
     
     
         10 . A charging handle retention system for use with an AR platform firearm, comprising:
 a charging handle having a top surface and a spring detent located on the top surface;   an upper receiver having a buffer end, a top side, an interior surface and a dimple located on the top side's interior surface, in a location configured to mate with the charging handle's spring detent.   
     
     
         11 . An enhanced bolt carrier group for use with an AR platform firearm, comprising:
 a bolt carrier having a barrel end, a buffer end, a top surface with a gas key location having a perimeter, two threaded holes within the location perimeter, a gas hole within the location perimeter, and a raised wall at the buffer end of the location perimeter;   and one or more selected from a group comprising a gas key and an anvil, wherein the gas key comprises a bottom surface and a back end, and the gas key bottom surface is configured to attach to the gas key location, and the gas key back end is configured to contact the wall when attached; and   the anvil comprises a bottom surface, a back end and a lug located on the bottom surface, wherein the anvil bottom surface is configured to attach to the gas key location, and the anvil back end is configured to contact the wall when attached, and the lug is configured to mate with the bolt carrier's gas hole.   
     
     
         12 . An enhanced direct impingement gas system for use with an AR platform firearm, comprising:
 an upper receiver with a gas tube hole;   a barrel with a muzzle end, a top side, an outer surface, a gas block stop, and a gas hole;   a gas block with a threaded gas tube hole exit; and   a gas tube with a straight shape, a threaded gas block end, an upper receiver end and a ferrule configured to encircle the gas tube at its gas block end;   wherein the ferrule is configured to be tightened upon installation of the gas tube into the gas block's gas tube hole exit, cinching the gas tube and creating a leak proof connection; and   wherein the upper receiver's gas tube hole and the gas block's gas tube hole exit each have an equivalent elevation distance from the top side of the barrel.   
     
     
         13 . An enhanced gas system for use with an AR platform firearm, comprising:
 a barrel with a top side, an outer surface, a gas block stop, a notch in the gas block stop, and a gas hole; and   a gas block with a breech end, and a key on the breech end; and   wherein the gas block key is configured to fit into the gas block stop notch to ensure proper alignment and placement of the gas block on the barrel and in relation to the barrel's gas hole.   
     
     
         14 . An enhanced gas system for use with an AR platform firearm, comprising:
 a barrel with a muzzle end, an outer surface, a gas block stop, a gas hole, and threading on the outer surface located between the gas hole and the muzzle end;   a gas block with a muzzle end; and   a gas block jam nut with a threaded inner surface;   wherein the gas block jam nut is configured to be torqued onto the barrel, holding the gas block's muzzle end in place on the barrel.   
     
     
         15 . An interchangeable gas system for use with an AR platform firearm, comprising:
 the enhanced direct impingement gas system of claim  12 ;   a bolt carrier, comprising a top surface with a gas key location, screw holes, a gas hole and a rear wall;   a gas key configured to attach to the gas key location;   a gas piston kit; and   an anvil configured to attach to the gas key location;   wherein the gas key location has a perimeter, and the screw holes and gas hole are located within said perimeter, and wherein the rear wall is located on said perimeter.   
     
     
         16 . An expansion chamber system for use with a firearm, comprising:
 a barrel, comprising a gas hole, a vent hole, a muzzle end, an outer surface, and threading on the outer surface between the vent hole and the muzzle end;   a rear support collar that fits and sets on the barrel between the gas hole and the vent hole;   an expansion chamber having a breech end and a muzzle end, and being configured to surround the barrel concentrically in a translational position including over the vent hole; and   an expansion chamber adaptor configured to threadedly attach to the barrel between the vent hole and the muzzle end;   wherein the real support collar and expansion chamber adaptor are configured to hold the expansion chamber in place on the barrel.   
     
     
         17 . A handguard for use with an AR platform firearm, comprising:
 an Arca style rail on a bottom surface, with one or more pockets; and   one or more weights, each having a shape configured to fit in the one or more pockets, and each being configured to be removably fastened into the one or more pockets.   
     
     
         18 . A handguard attachment mechanism for use with an AR platform firearm, comprising:
 a barrel nut; and   a handguard with an outer surface, a breech end, and a plurality of locks with claw hooks located at the breech end;   wherein each lock is configured to threadedly receive a bolt; and   wherein when the handguard's breech end is positioned around the barrel nut, the claw hooks are configured to extend behind and around the barrel nut; and   wherein tightening of each bolt causes retraction of its associated claw hook, and tightening of a connection between the barrel nut and handguard.   
     
     
         19 . A handguard extender for use with an AR platform firearm, comprising:
 a U-channel beam with a length, a bottom surface having periodic holes and an Arca rail shape, and at least two of right, left and bottom inside surfaces with slots;   wherein the U-channel beam is configured to slide on rails located on at least two of bottom and sides of a handguard, contacting skid pads made of lubricious material and installed onto the rails of the handguard; and   wherein the U-channel beam is further configured to attach to a handguard's bottom surface with one or more locking pins that pass through one or more of the periodic holes; and   wherein the length of the U-channel beam is configured to extend forward beyond a barrel muzzle, when the handguard is installed on a barrel.   
     
     
         20 . An AR platform firearm with extended scope range, comprising:
 an upper receiver with a barrel end, a buffer end and a top surface; and   a Picatinny rail with a barrel end, a buffer end and an angle of inclination;   wherein the Picatinny rail is located on the top surface of the upper receiver; and   wherein the angle of inclination of the Picatinny rail as compared with the upper receiver's top surface is greater than zero degrees.