CMMG Endeavor 20" Upper .22 ARC with 1:7 Twist Rate and M-LOK Rail – Rifle-Length with BCG and CH – Armor Black – 28B3D0CAB

While 5.56x45mm remains a staple, the .22 ARC introduces 22-250 caliber performance to the lightweight AR-15 (MK4) platform and the ENDEAVOR MK4 upper group with its 20 inches barrel maximizes ballistic potential. Each ENDEAVOR upper group includes the bolt carrier group along with a meticulously selected array of parts and accessories.