So I see that nobody responded to your question about using copper jacketed bullets in the muzzle loader so maybe I can share my experience with them... I have had several different muzzle loaders through years and about 6 years ago I bought one of the new "inline" style break open .50 cal. models. It was a used gun and the original owner had clearly done a poor job of caring for and cleaning it as the inside of the barrel was pretty rough with pits. It was a stainless barrel but that doesn't mean it indestructible, lol.. However due to the rough bore I decided to try out the .45 cal saboted rounds. Since then I have tried them all, Thompson, Powerbelts, Traditions, etc but my favorite is the Barnes 250 gr. For me I haven't had any issues, they shoot reliable groups at 100 yards in my rough barrel of 1-2 inches, they shoot about 3 inches lower at 100 than at 50 yards, and yes most of my shots have gone completely through the deer, with the exception of a doe I shot back in December. She was quartered away from me and moving at about 65 yards when I took the shot and was aiming for the far shoulder. It passed through the ribs and after hitting the shoulder it stopped in the meat. I was able to recover it when I boned it out. I don't know if you are familiar with Barnes bullets but their muzzleloader bullets perform as ed just like all their others, perfect expansion just as advertised. She went about 40 yards and piled up. I am completely satisfied with them. One last thing, ssshhhh, don't tell anyone... but I also use smokeless powder behind them..... but that's another story..