I started Muzzle loader hunting two seasons ago so this is my third season. I have a CVA Optima Pro and the book that came with it stated the recommended round for the gun were Power belt bullets. I did not know much about muzzle loaders so I went with power belts in a 245 grain aero tip. I started out shooting 100 grains of powder (2 pellets) and I felt the accuracy was not there out to 100 yards, so this season I upped the powder charge to 150(3 pellets) with the same bullet, it seems to shoot more consistently.

Here is the issue I am having. I cover my scent pretty well (at least i think so) and i see plenty of deer and usually have them very close to me in my tree stand(5-30 yards). I have shot 4 deer with my muzzle loader in the last 3 seasons (2 with 100 grains and 2 with 150 grains) and all 4 have been within 40 yards. the first one I shot him and he went 10 feet and fell, no problem. The other 3 I shot them and only 1 had a blood trail and exit wound. The other 2 were within 20 yards and both bucks. I hit them behind the shoulder (1 with 100 grains and 1 with 150) and both deer had no exit wound and barely any blood at the spot i hit them in and little to no blood on the trail. When i opened the deer up (because I did not give up and found them) it looks like the bullet exploded inside of them.

Sorry about the long drawn out story I just wanted people to have the background facts. My question is, is this because of the bullet, the powder load, a combination of both, or the range. Also should I be using another kind of bullet and has any one had this happen to them?