If you go G&G id recomend replacing the Piston Head O-ring with a Viton O-ring (there great piston heads if you keep the spring stock or keep to a M110 or less) the pistons are great and already have the second tooth removed so its great for high ROF set ups plus its good grade polycarb. Besides the O-ring The other issue is the trigger contacts, after a good break in they may or may not work on a full trigger pull (seems to vary with different baches of guns). All this fix requires is to split the mech box and lightly crimp the trigger contacts so they make contact when the trigger is fully pulled back. Other than that there solid guns.
All right, they're on our left, they're on our right, they're in front of us, they're behind us... they can't get away this time!
- Lieutenant General Lewis B."Chesty" Puller (when surrounded by 8 enemy divisions)
Born to fight, trained to kill, ready to die, but never will.