The Robinson Armament Co. XCR is a multi-caliber, gas piston weapon system developed by Robinson Armament Co. for U.S. Special Operations Command (SOCOM) to satisfy the requirements of the SOF Combat Assault Rifle, or SCAR competition, but was disqualified on a technicality due to late delivery of blank firing adapters. Robinson Armament continued development and the XCR is now being offered to law enforcement, the military and general public. Deliveries of the rifle began in mid-2006.
The XCR utilizes a heavy duty bolt and extractor connected to an AK-47 type gas piston. The bolt and extractor are designed and patented by Robinson Arms, and promoted as offering higher performance over M16/M4 type bolts. Other features include a folding stock which eases storage space consumption and deploying from a vehicle, though M4 Carbine style stocks for those who prefer length of pull adjustments; it also has a monolithic top Picatinny rail with side and under-barrel rails, and forward assist integrated into left-side charging handle. Approximately 3,000 XCR carbines have been sold since its introduction in 2006.
The XCR can be converted to various calibers and barrel lengths within a few minutes due to the modular design without the need for a trained armorer.
In addition to conversion kits, factory guns in the alternate calibers are also sold.
The XCR employs a Kalashnikov type, gas operated action with the bolt carrier attached to a short-stroke gas piston; the gas chamber is located above the barrel.
The proprietary bolt is a three-lug design that locks onto the barrel extension leaving the upper receiver unstressed. There is no need to check the headspace when changing barrels. A steel fixed ejector is attached to the inside of the receiver, held in place by two bolts. The manufacturer claims this design provides stronger ejection than what is offered on the AR-15’s spring loaded ejector design. The ejection pattern is to the two o'clock position of the operator, with an optimum distance of 15ft to 20ft depending on ammunition type and gas setting.
Magazines are STANAG 4179 type.
The quad rail system is integrated into the upper receiver and compatible with most 1913 picatinny devices. The top rail is monolithic and 17” long, providing a rigid, uninterrupted plane for mounting optics and BUIS (Backup Iron Sights); the 3, 6, and 9 O'clock Position Rails are 8" long.
The Robinson Arms XCR is currently available as a factory gun in 5.56x45 NATO, 6.8 Remington SPC and 7.62x39. The XCR price can vary depending on configuration, averaging between $1,400 and $1,600 for semi-automatic versions. Select fire military and law enforcement models are also available.