Yes I have only used the same powerbelt in the 245 and 295 gr copper bullets over the years. Send me some links on whatever you find on a good available .45. It is definitely a concern. Obviously for this gun they went with the .45 cal to get better ballistics speed accuracy etc. Many of the manufacturers mostly have 50 cal. The more I think about my previous experiences the less good vibes I have for PB.
1st Deer shot at 30 yards straight through the vitals. Ran 50 yards and he was done.
2nd deer shot at 90 yards quartering away ran 300 yards had very little blood trail and thought I had completely missed by the way the deer acted. Got lucky and found him the next ridge over piled up.
3rd deer hit at 151 yards and had to track it all over the mountain over 2 hours to finally get him finished off.
4th deer hit in hind quarters exploding the bullet which my friend finished off hitting in the vitals.
5th deer hit in the front shoulder ended up chasing for about a quarter of a mile before finishing him off. Another one we were lucky to find with lack of blood trail.
6th Elk shot in the front shoulder at 40 yards that ran off leaving 0 blood never to be seen again.
7th Elk took 2 shots at 80 yards behind the shoulder through both lungs ran 100 yards and piled up.
8th deer last year 90 yards through both shoulders and ran 50 yards and was done.
While we only lost the one animal things could have turned out worse. More than once I have thought that I would have been better off with a bow and arrow with some of the hangfires, misfires and other issues with muzzleloaders. Hopefully this gun at least goes off most of the time.