While I agree that many people shoot too far back, you certainly don't want to shoot too far forward with a muzzleloader. When my son was 16, he drew an early muzzleloader tag for elk in Arizona. The first morning out, we got on a really nice 6x7 bull and he had a quartering to shot at a little over 150 yards. He hit the bull right on the point of the shoulder, shooting a 50 caliber, 338 grain powerbelt bullet. It nearly knocked the bull off his feet, but he recovered and ran past us, holding up his injured right front leg. I figured the bull would die quickly, so we gave him about 5-10 minutes and started searching for him. Long story short, we found no blood, no elk and we looked for about 4 hours that day. The next morning, we went back again to look and we found the bull. eHe was chasing cows, and keeping satellite bulls at bay. He was limping badly, but we could not keep up with him and his harem as they traveled. Later that day, we talked to the Game Warden and he suggested we keep hunting as there was no way in his opinion, or mine, that the bull had suffered a fatal wound. We both concluded that the bullet had likely hit the shoulder blade and never entered the chest cavity.
We kept hunting and the next evening my son shot a beautiful 6x5 BEHIND the shoulder at about 60 yards. The bull ran in a little circle and tipped over right in front of us. That bullet was lodged on the far side hide, and totally shredded his lungs.
If you're shooting a muzzleloader, especially with a lighter, pistol type bullet, be sure to sneak that bullet behind the shoulder, don't try to punch through it.