Mar 24, 2026

US12584703 - Cam race for improved upper receiver longevity

An apparatus and methods are provided for a cam race for improving the longevity of an upper receiver of a direct gas operated firearm. The cam race provides a hardened slide face and a corner surface for a cam pin comprising a bolt carrier group of the firearm. The cam race is configured to be secured into a window disposed in the upper receiver. The window is surrounded by a counterbored area that receives a back plate of the cam race. The counterbored area and the thickness of the back plate cooperate such that the corner surface and the slide face are positioned to receive the cam pin during reciprocal movement of a bolt carrier group within the upper receiver. The cam race is retained in the upper receiver by fasteners that are tightened into threaded holes in the counterbored area.

Assignee: SureFire, LLC
Inventors: Barry William Dueck, Henry Mumford, Michael Standen, Eric Chow
Filing date: 2024-09-25

firearmupper_receivercam_racedirect_gas_operated

The patent describes a cam race designed to enhance the durability of the upper receiver in direct gas-operated firearms by providing a hardened slide face and a corner surface for the cam pin. This cam race is secured within a recess in the upper receiver, utilizing a backplate and fasteners to ensure stability during the operation of the bolt carrier group.

Claim 1

1 . An assembly for improving the longevity of a direct gas operated firearm, the assembly comprising: a cam race configured to be secured into a recess disposed in an upper receiver wherein the cam race comprises an elongated backplate having a raised portion wherein the backplate is configured to be fastened into a counterbored portion disposed in a sidewall of the upper receiver such that the raised portion extends through an opening in the sidewall and further wherein the counterbored portion is disposed on an exterior of the sidewall, such that the backplate is fastened onto an exterior of the upper receiver; a slide face of the cam race for supporting a cam pin in sliding contact; threaded holes positioned along a length of the cam race; and fasteners for engaging the threaded holes to secure the cam to the upper receiver. a cam race configured to be secured into a recess disposed in an upper receiver wherein the cam race comprises an elongated backplate having a raised portion wherein the backplate is configured to be fastened into a counterbored portion disposed in a sidewall of the upper receiver such that the raised portion extends through an opening in the sidewall and further wherein the counterbored portion is disposed on an exterior of the sidewall, such that the backplate is fastened onto an exterior of the upper receiver; a slide face of the cam race for supporting a cam pin in sliding contact; threaded holes positioned along a length of the cam race; and fasteners for engaging the threaded holes to secure the cam to the upper receiver.

Google Patents

https://patents.google.com/patent/US12584703

USPTO PDF

https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/12584703