I'm using remington 2 3/4" gun club target loads 7 1/2 shot at 1 1/8 at 1200fps, with the heavy piston, so far no problems. This is also out of a brand new gun that aint broken in yet. Some earlier posts say to break it in using heavier loads if having problems running light loads. Also they say running 1 1/8 is about the lightest you can run it. That's what I found doing searches. I don't have the light piston its about $100.00, I'll just keep shooting the 1200fps loads to make sure I'm knocking steel down. Hope this helps. I'm a newbee and learing alot of the forum thanks to all those that share there info.