Monolithic upper receiver assembly

1. An upper receiver assembly comprising:

an outer member comprising an upper rail; and

an inner member comprising at least one selected from the group of a pivot pin lug and a takedown pin lug, wherein:

the inner member is disposed at least partially inside the outer member;

the upper rail extends as a single continuous member from an opening for a charging handle to a forward end of a handguard portion of the outer member; and

the outer member is over molded relative to the inner member to permanently attach the outer member and the inner member.

2. The upper receiver assembly of claim 1 , wherein:

the outer member comprises an ejection port;

the inner member comprises an ejection port; and

the ejection port of the inner member is at least partially aligned with the ejection port of the outer member.

3. The upper receiver assembly of claim 1 , wherein the handguard portion is disposed forward of the pivot pin lug.

4. The upper receiver assembly of claim 1 , wherein the inner member comprises a metallic material.

5. The upper receiver assembly of claim 1 , wherein the outer member comprises a polymer material.

6. The upper receiver assembly of claim 1 , wherein the outer member comprises an aft portion and a forward portion.

7. The upper receiver assembly of claim 6 , wherein:

the aft portion comprises an ejection port and the opening for the charging handle;

the forward portion comprises an array of openings; and

the upper rail is a single continuous member extending along both the aft portion and the forward portion.

8. The upper receiver assembly of claim 6 , wherein the outer member further comprises a transition portion located between the aft portion and the forward portion.

9. The upper receiver assembly of claim 8 , wherein the transition portion corresponds to the location of a barrel nut, which attaches a barrel to the inner member.

10. The upper receiver assembly of claim 1 , wherein the opening for the charging handle is disposed at a rear end of the outer member.

11. An upper receiver assembly comprising:

an outer member comprising an upper rail, an aft portion, and a forward portion;

an inner member comprising an ejection port;

at least one of a pivot pin lug and a takedown pin lug; and

a plurality of fasteners for securing the outer member and the inner member relative to one another, wherein:

the inner member is disposed at least partially inside the outer member;

the outer member comprises an opening for a charging handle; and

at least one of the fasteners is disposed forward of the ejection port.

12. The upper receiver assembly of claim 11 , wherein the forward portion comprises a handguard portion.

13. The upper receiver assembly of claim 11 , wherein:

the outer member comprises an ejection port; and

the ejection port of the inner member is at least partially aligned with the ejection port of the outer member.

14. The upper receiver assembly of claim 11 , wherein the opening for the charging handle is disposed at a rear end of the outer member.

15. The upper receiver assembly of claim 11 , wherein the outer member is an extrusion.

16. The upper receiver assembly of claim 11 , wherein the outer member comprises a polymer material.

17. The upper receiver assembly of claim 11 , wherein:

the aft portion comprises an ejection port and the opening for the charging handle;

the forward portion comprises an array of openings; and

the upper rail is a single continuous member extending along both the aft portion and the forward portion.

18. The upper receiver assembly of claim 11 , wherein the outer member further comprises a transition portion located between the aft portion and the forward portion.

19. The upper receiver assembly of claim 18 , wherein the transition portion corresponds to the location of a barrel nut, which attaches a barrel to the inner member.

20. The upper receiver assembly of claim 19 , wherein at least one of the fasteners attaches the outer member to the barrel nut.

21. An upper receiver assembly comprising:

an outer member comprising an upper rail, an aft portion, a forward portion, and a transition portion located between the aft portion and the forward portion;

an inner member comprising at least one selected from the group of a pivot pin lug and a takedown pin lug; and

at least one fastener for securing the outer member and the inner member relative to one another, wherein:

the inner member is disposed at least partially inside the outer member;

the transition portion corresponds to the location of a barrel nut, which attaches a barrel to the inner member; and

the at least one fastener attaches the outer member directly to the barrel nut.

22. The upper receiver assembly of claim 21 , wherein the outer member comprises a polymer material.

23. An upper receiver assembly comprising:

an outer member comprising an upper rail, an aft portion, a forward portion, and an ejection port;

an inner member comprising an ejection port; and

at least one of a pivot pin lug and a takedown pin lug, wherein:

the inner member is disposed at least partially inside the outer member; and

the ejection port of the inner member is at least partially aligned with the ejection port of the outer member; and

the outer member is over molded relative to the inner member to permanently attach the outer member and the inner member.

24. The upper receiver assembly of claim 23 , wherein the outer member comprises a polymer material.

25. The upper receiver assembly of claim 1 , wherein the over molding process comprises first manufacturing the inner member and locating the inner member within a cavity of a molding machine and subsequently injecting polymer in liquid form into the cavity to form the outer member.

26. The upper receiver assembly of claim 11 , wherein the outer member is over molded relative to the inner member to permanently attach the outer member and the inner member.