Had a friend from out of state hand me his 7mm Rem mag to shoot and tell me, "be careful it's got a lot of recoil!" I said, "oh, I expect it has less than my 12 gauge deer gun with slugs!" He sorta looked at me like "why the hell would you shoot slugs out of a shotgun?" "Because.... Indiana." It WAS pretty tame in comparison.
I always dreaded shooting that thing to confirm zero each year. Bugs, allergies, shoulder sore, sweating,.... Headache.
I got myself with the scope just a little one time. Where I sit, I have deer coming from any direction, so Ive shot left handed, twisted all around behind me, leaning out, etc. I didnt have the butt on my shoulder quite right and it slipped as I fired. Deer was dead, but I had a little scuff over my eye. I wear my hat to my eyebrows so that saved me.
Unfortunately the 458 isnt exactly a walk in the park to shoot, but its better.
I know every gun's felt recoil is different (weights and stock dimensions vary), but according to the charts, a 12 gauge with 3" rifled slugs has recoil that is nearly identical to that of a comparable weight .375 H&H.
If that's true, it's probable that the .458 Winchester Magnum outdoes even 3" slugs.
I'm certain that a .458 Lott, .460 Weatherby, or .577 Tyrannosaur would make 3" slugs look almost mild by comparison.