I think the Air Venturi HellBoy M4 CO2 BB Rifle is a super addition to the replica rifle lineup. I know we all wish it had blowback operation and shot in full auto mode too but there are trade-offs here and you can still have boat loads of fun shooting the Air Venturi HellBoy M4 CO2 BB Rifle even in semi auto only mode. The fact that it does not have blowback allows for some generous fps velocity and more shots per CO2. It looks really great, feels really great and shoots really great all in a mostly metal build which is what everyone has been asking for and at a reasonable price. I think the Air Venturi HellBoy M4 CO2 BB Rifle is a total winner and recommend it 100%. You will not be disappointed!