metaltac mt6604 airsoft gun m4a1 carbine gas blow back airsoft rifle(Airsoft Gun) 1:1 Scale of a M4A1 Carbine with blow back recoil. Comes with a 50 round gas magazine and speedloader with adapter. Constructed from durable ABS plastic, has semi-automatic, full auto, and safety feature with metal internals. Velocity of approximately 400 FPS using 0.20g BBs. Gas operated rifle. Nice blow back kick per shot for realism.