New York Hunter: I know that Buffalo Bore makes some 'stepped up' or heavy loads, but nothing beyond pressure limitations. I have seen the results of comparisons using Buffalo Bore ammo and it shoots, or appears to shoot as accurately if not better than most. My brother tried some of their 45-70 ammo and said that although he starting flinching after about 10 rounds, it hit where he pointed the rifle. HTH. Mikey.