Rifle upper receiver with integral magazine well

• US 20110094136A1
• Filed: 10/23/2009
• Published: 04/28/2011
• Est. Priority Date: 10/23/2009
• Status: Active Grant

• Current Assignee: Michael Dwain Zimmerman
• Original Assignee: Michael Dwain Zimmerman
• Inventors: Zimmerman, Michael Dwain
• Granted Patent: US 8,484,877 B2
• Time in Patent Office: Days
• US Class Current: 42/6
• CPC Class Codes: B21C 23/14 Making other products
• CPC Class Codes: F41A 21/484 using interlocking means, e.g. by sliding pins
• CPC Class Codes: F41A 3/66 Breech housings or frames; Receivers
• CPC Class Codes: F41C 23/16 Forestocks; Handgrips; Hand guards pump-action guns F41C7/02

Abstract

Rifle upper receivers with integral magazine wells include an extruded elongate inverted U-shaped channel with an interior bore. The interior of the channel has elements formed as surfaces of extrusion. The surfaces of extrusion provide guidance and support for a magazine and trigger guard assembly pins. The present invention is manufactured by extruding an elongate tube in a closed-box profile with an interior bore, milling a series of slots into the top of the tube, machining a bottom channel opening by removing portions of the bottom of the tube, machining holes in the sides of the tube, and machining a recess in the top of the interior of the tube.

Claims

1. A rifle upper receiver with integral magazine well comprising:

an extruded elongate inverted U-shaped channel with an interior bore;

the channel having a top, a bottom, a left side, and a right side;

the channel having front, rear, and bottom openings;

the channel having an interior with elements formed as surfaces of extrusion; and

the surfaces of extrusion providing guidance and support for a magazine and trigger guard assembly pins.

2. The upper receiver of claim 1, further comprising:

a plurality of trigger guard assembly mounting holes in the left side and right side of the channel;

the trigger guard assembly mounting holes receiving trigger guard assembly attachment pins; and

the trigger guard assembly attachment pins removably securing a trigger guard assembly to the channel.

3. The upper receiver of claim 1, further comprising:

a guide rod channel defined by a slot in the top of one side of the channel;

the guide rod channel receiving a guide rod and spring; and

the guide rod guiding the reciprocating motion of a bolt assembly within the interior bore of the channel.

4. The upper receiver of claim 1, further comprising:

an ejection port defined by a bore in one side of the channel; and

the ejection port being in communication with the interior bore of the channel.

5. The upper receiver of claim 1, further comprising the top of the channel comprising a military specification top rail.

6. The upper receiver of claim 1, further comprising:

a plurality of bottom rail mounting holes in the bottom of the left side and right side of the channel;

the bottom rail mounting holes receiving bottom rail attachment screws;

the bottom rail attachment screws removably securing a bottom rail to the channel; and

the bottom rail removably covering a portion of the bottom of the channel.

7. The upper receiver of claim 1, further comprising:

a recess in the top of the interior bore of the tube;

the recess receiving a recoil lug; and

the recoil lug protruding from the top of a trunnion.

8. The upper receiver of claim 7, further comprising:

the trunnion having a barrel tenon bore; and

the barrel tenon bore receiving a barrel tenon attached to a barrel.

9. The upper receiver of claim 7, further comprising:

the trunnion having a magazine pin hole; and

the magazine pin hole receiving a magazine pin protruding from a magazine.

10. The upper receiver of claim 8, further comprising:

the trunnion having a barrel retainer screw hole;

the barrel retainer screw hole threadedly receiving a barrel retainer screw;

the barrel retainer screw attaching a barrel retainer to the trunnion;

the barrel retainer cantilevering the barrel into place within the tube, leaving the barrel projecting outward with an unsupported forward end.

11. The upper receiver of claim 7, further comprising the step of:

boring a plurality of trunnion attachment holes in the left side and right side of the channel;

the trunnion attachment holes receiving trunnion attachment screws; and

the trunnion pins removably securing the trunnion to the channel.

12. The upper receiver of claim 1, further comprising:

a recoil pin mounting hole in the left side and the right side of the channel;

the recoil pin mounting holes receiving a recoil stop pin; and

the recoil stop pin limiting rearward motion of a bolt assembly within the interior bore of the channel.

13. A method of manufacturing a rifle upper receiver with integral magazine well comprising the steps of:

extruding an elongate tube in a closed-box profile with an interior bore having a top, a bottom, a left side, a right side, and front and rear openings;

the tube having an interior with elements formed as surfaces of extrusion that provide guidance and support for a magazine and trigger guard assembly pins;

machining a bottom channel opening in the elongate tube by removing at least a portion of the bottom of the tube;

a portion of the bottom channel opening comprising a magazine well; and

the magazine well receiving a magazine.

14. The method of claim 13, further comprising the step of:

boring a plurality of trigger guard assembly mounting holes in the left side and right side of the tube;

the trigger guard assembly mounting holes receiving trigger guard assembly attachment pins; and

the trigger guard assembly attachment pins removably securing a trigger guard assembly to the tube.

15. The method of claim 13, further comprising the step of:

machining a guide rod channel into the top of one side of the tube;

the guide rod channel receiving a guide rod and spring; and

the guide rod guiding the reciprocating motion of a bolt assembly within the interior bore of the tube.

16. The method of claim 13, further comprising the step of:

boring an ejection port into one side of the tube; and

the ejection port being in communication with the interior bore of the tube.

17. The method of claim 13, further comprising the step of:

milling a plurality of slots into the top of the tube; and

the milled top of the tube comprising a military specification top rail.

18. The method of claim 13, further comprising the step of:

boring a plurality of bottom rail mounting holes in the bottom of the left side and right side of the tube;

the bottom rail mounting holes receiving bottom rail attachment screws;

the bottom rail attachment pins removably securing a bottom rail to the tube; and

the bottom rail removably covering a portion of the bottom channel.

19. The method of claim 13, further comprising the step of:

boring a recess into the top of the interior bore of the tube;

the recess receiving a recoil lug; and

the recoil lug protruding from the top of a trunnion.

20. The method of claim 19, further comprising:

the trunnion having a barrel tenon bore; and

the barrel tenon bore receiving a barrel tenon attached to a barrel.

21. The method of claim 19, further comprising:

the trunnion having a magazine pin hole; and

the magazine pin hole receiving a magazine pin protruding from a magazine.

22. The method of claim 20, further comprising:

the trunnion having a barrel retainer screw hole;

the barrel retainer screw hole threadedly receiving a barrel retainer screw;

the barrel retainer screw attaching a barrel retainer to the trunnion;

the barrel retainer cantilevering the barrel into place within the tube, leaving the barrel projecting outward with an unsupported forward end.

23. The method of claim 19, further comprising the step of:

boring a plurality of trunnion attachment holes in the left side and right side of the tube;

the trunnion attachment holes receiving trunnion attachment screws; and

the trunnion pins removably securing the trunnion to the tube.

24. The method of claim 13, further comprising the step of:

boring a recoil pin mounting hole in the left side and the right side of the tube;

the recoil pin mounting holes receiving a recoil stop pin; and

the recoil stop pin limiting rearward motion of a bolt assembly within the interior bore of the tube.