I was shooting roughly 71lbs of KE last year with these. The doe was a perfect broadside heart shot that passed through skipping 20+ yards on the ground behind her before stopping, and the other buck I shot last year was another quartering away that went in behind the last rib and passed through just behind the far shoulder at about 17 yards. Penetration even when I hit ribs and shoulder blades was as good as any fixed head I have used, they seem to waste a lot less energy opening than traditional large diameter heads. The Vortex heads I used to shoot back in the day didn't penetrate like these do.