Gremilin, if you have the USA mags that everyone is so leary of, they are made of steel, not aluminum. And some USA mags actually can work. The problem is they are built so poorly, they will rarely work for very long or stand up to be dropped etc. They may work now, but ususally dont work for long because feed lips bend easily and bodies get dented easily. Springs tend to weaken and set much quicker too.