The .450Mar is slighty better than the .45/70 in there factory form but the .45/70 can be handloaded to hotter specs. I use a Marlin .444Mar.and use 265g Hornady's and they flatten any pig! at present I am toying with my Winchester 1895 in .405Win and Savage 99 in .358Win . I presume your use of these calibres is for pigs?

Steve