I am considering installing a 20 lb. spring in my Glock 20 that has a 6" barrel because the heavy spring is supposed to work better for the hot ammo. from Double Tap and others. Anyone have any experience with heavier springs? Also I am switching to lead free ammo because it has higher velocity and I have learned that it is almost impossible to clean all the lead fragments out of game shot with lead bullets; plus lead is highly toxic to some scavenger birds, condors, eagles, etc.