Floyd Paterson, the former heavyweight champ, had a chin of Dresden china and probably spent as much time on the canvas as he did on his feet. Muhammad Ali had a chin of iron, and absorbed some of the most savage beatings in ring history without going down. He could be decked only rarely, and knocked out, never. How come? No one has an answer.
So it is with recoil. Some people can take a ton of it and walk away with a spring in their step and a song in their heart. Others run shrieking for the ice bag and the Ibuprofin if they fire anything bigger than a BB gun.
It doesn’t seem to relate to body size. I know small guys who can shoot horrendous rifles with no trouble, and immense humanoids who swoon at the sight of a .30/06. As a rule, the upper limit for most rifleman is a .41-caliber cartridge such as the .416 Remington or Rigby. Both fire 400-grain bullets at 2,300 fps or so. When you get up to the .458, with 500 grains at 2,000 fps (or a little less) and about 60 foot-pounds of recoil, most people would rather not, thanks. And with bigger cartridges like the .458 Lott and .450 Dakota 500 grains, 2,300 fps), even the toughest riflemen grow pale and begin to tremble.
The worst-kicking rifle I’ve ever used is the .378 Weatherby. It comes back at you so fast you can’t roll with it, and it’s the only rifle I’ve ever sold because I feared it.
The worst thing you can do if you want to learn to shoot a big rifle is use a Lead Sled. The way you learn to take a punch is by getting punched. The way you learn to handle lots of kick is by getting kicked. The Lead Sled absorbs just about all the recoil, and prevents you from becoming a manly man. (If you are a woman, this is obviously not a consideration.) Take your whupping and learn to live it.