300 4,Kwa sr10, tightened the body very solid now, shimmed the crane stock no wobble, shimmed the gears, AOE, sorbo cylinder head, stainless steel cylinder, retro arms new gen metal rack piston love these, pom ported piston head with compression bearings, cleaned up wiring with Dean's, custom high torque motor strong, umbrella armory motor grip, this is a 1.72J gun with .32s, that's 430 with .2g, this lifts heavy ammo no problem I recommend nothing lighter than a .28 but .3g + is advised.