I'll admit that a .338 Win Mag is about the limit of what I can shoot properly and even that isn't something I enjoy.
You may be making the common error of assuming it's the caliber/cartridge that's unpleasant, which is rarely the case. Rather, it's the fit of the gun to the shooter that is most important!
My 338 Mag Sako kicks the bejesus out of me, and my Kimber 375 H&H shoots like a lamb in comparison. Why should a 225 gr bullet @ 2900 fps muzzle velocity hurt me more than a 300 gr bullet @ 2600 fps? Primarily, it's the fit of the rifle to the shooter.
BTW, Ruger No. 1's are notorious for kicking the schit out of taller/longer-necked guys. All the guys I know who love Ruger No. 1's are shorter/stockier guys.
Your "limit" is probably not as low as you think it is.
