Patent ID: 11898589
Assignee: LWRC INTERNATIONAL LLC
Field: Other special machines (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 6:
7. A gas operated firearm comprising:
an upper receiver having a forward end with an externally threaded extension and an opening for receiving an operating rod of a gas operating system;
a barrel having an annular flange proximate a rear end of said barrel; and
a barrel nut assembly for connecting said barrel to said upper receiver, said barrel nut assembly including:
an internally threaded barrel nut threadingly secured to said externally threaded extension of the receiver and a front end of the barrel nut being configured to receive the rear end of the barrel therein, said barrel nut having a throughbore adjacent to a periphery of said barrel nut that is aligned with said receiver opening to receive said operating rod therethrough, wherein the front end of the barrel nut has an integrally formed exterior flange having at least two squared off sections to render a forward face of the barrel nut substantially square, the at least two squared off sections configured to be captured within a fixture that rotationally restrains said barrel nut; and
a locknut having external threads that engage with the internally threaded barrel nut to compressively engage and secure said barrel in position against said receiver, a back side of said barrel annular flange being seated against a forward face of the threaded extension of the receiver.