Be carefull loading your own sub-sonic ammo. The problem is that most folks think you just put in less powder and your ok, but that less powder leaves alot of empty space in the case. You may not get good flame propagation from the primer thru the powder, and the low bullet speeds may lead to baffle strikes that manufacturer's won't warrenty. I know GemTech will only fix a can with Engle or Black Hills ammo.