Barrett REC7

The Barrett REC7 (designation stands for "reliability-enhanced carbine") is an American firearm manufactured as a selective-fire fully-automatic and semi-automatic rifle by Barrett Firearms. It is an M4 carbine utilizing a short-stroke gas piston system and is available in either 5.56×45mm NATO or 6.8mm Remington SPC. The REC7 is Barrett's second AR-pattern rifle chambered for the 6.8mm Remington SPC cartridge, the first being the Barrett M468 rifle. The 6.8 SPC-chambered M468 rifle employed the same Stoner bolt and carrier piston system as the M4.