Last summer I saw an interview with the President of Powerbelt Co. on tv.
He was talking about the new Platinum Powerbelt which, he said, was designed to "give better penetration" for big deer, and elk.
I guess he had heard the complaints about the miserable performance of his bullets.
Well, a guy over on another forum was going elk hunting this year, he had never hunted with a muzzleloader. He tried his Encore with the new Platinum Powerbelt. He killed a big bull elk with a shoulder shot with the big Platinum Powerbelt. I believe he used 90 grains of 777, can't remember exactly.
Based on this experience, I believe you will be ok on the big game with the Platinum Powerbelt.
Too bad it took the company five years to figure it out.