"This mag will turn your ordinary m4/m16 or compatible gun into an intimidating sexy beast. my brother and i both got one and took it to a match. we both usually run mid caps so remembering to wind it would have been an issue, except it keeps enough ammo at the ready to take out a squad and move to an safe position. by that time i would have reloaded a mid cap at least once, but instead i hit the pressure switch and kept playing. the only bad thing is my brothers will sometimes get a bb jammed in the winding mechanism. easy fix, but a little annoying on the field if you dont bring back up mags. my mag has worked great from day one however and cant find anything to complain about.