I would liken it with a muzzle loader since they shoot the same types of bullets at roughly the same speeds. I have found with out a doubt the heavier bullets perform better out of my muzzle loader. And I shoot the same .44 cal XTP bullet with a sabot. After moving up to 300 and then a 350 grn bullet the performance was even better yet each time as far as down range energy goes.

I would only assume you would get the same results with a handgun. You just need to find a happy medium between trajectory and down range energy. Recoil might be a factor in a handgun as well. I have never handgun hunted though.

Paul