I think 500grains is dead on the money about recoil tolerance.

When I first started shooting my 416 Rem I thought it was just too much gun. I started on exercises and an upper body routine because of incidental use of an available gym.Within 4 months I was able to tolerate the rifle much better and not just endure it. Muscle tone, stock fit, rifle control,and desire have a lot to do with good shooting.Poor muscle tone would allow the rifle just to drive deeply and shock the supporting structure of the shoulder. I feel toned muscle transmits the blow as more of a "push" IMHO.

My wife noted ?some improvement in her shooting of my 30.06 after a summer at the gym but that is hard to determine since she really doesn't enjoy hunting or shooting.

Like most things I think you gotta want it and work at it to get the best results.