I have had two experiences that I will never forget:

First was a Ruger M77 in 458 Win Mag no muzzle brake, not sure what the ammo was, but I shot 2 shots from a bench. My shoulder was black and blue for about a week and a half.

Second was a 460 Weatherby in a Mark V rifle no brake, one shot off the bed of a truck and that was enough for me.

I shot a 375 H&H and yes it hurt but not as much as the two listed above. I shoot a 300 Win, 338 Win, and a 270 Weatherby consistently with no complaints.