More weight is always a help with penetration, but a bullet that drives all the way thru a deer ,doubles in size and stops under the hide on the off side has done what it was made to do.I weighed one from my wifes deer that went from chest to back of ham that lost less than 15 grains of weight, 90 grains of 3fff at 10 yds. I want two holes in every thing I shoot if possible as where I hunt they can be out of sight in a couple of jumps. So far I can't find a cast that will shoot with the xtp ,but I am still working on it when finances allow.