I shot a doe with a 50 cal optima, 245gr Powerbelt over 100gr Triple 7 loose powder. I hit her in the shoulder at 50-60 yds quartering towards me. it fragmented, but still ended up in the lungs, no exit. She rolled backwards and dropped dead. Did the bullet fragment?? Yes, but still got the job done, very effectively. I believe as long as you got enough gun, a fast expanding bullet is good thing to transfer energy. Now if I was pistol hunting, I would opt for a penetrating bullet, but in an in-line muzzleloader, fast expanding is just fine.