LWRC International, LLC, formerly known as Land Warfare Resources Corporation, is a CAGE defense contractor and firearms manufacturer, founded in 1999, and based in Cambridge, Maryland. From 1999 to January 2006, the company was primarily engaged in research and development. In January 2006, the company was purchased in a management buyout by U.S. Army veteran Pat Bryan. After reorganization, the company moved into full-fledged firearms manufacturing. Along with the management buyout, LWRC absorbed Grenadier Precision Ltd. Company of Texas.
The company produces several weapons based on the M4 carbine, which use a proprietary short-stroke self-regulating gas piston system and bolt carrier design. This system prevents trapped gases from contacting the bolt carrier or receiver of the weapon, which reduces the heating and carbon fouling of the internals, simplifies field maintenance, and improves reliability.