My "manly handgun" shoots a .45-70 405 grain in a 14" barrel.
Humdi,
Recoil management begins between the ears. Don't be afraid of it instead learn to manage it. Recoil can never be eliminated but you can learn techniques to mitigate the effects. The biggest thing is learn how to redirect the energy so the impact on you is minimized. Go to the range and watch people shooting heavy recoiling guns, the ones not being beaten to death are redirecting the energy. The phrase "roll with the punches" illustrates the idea. Google "Taming recoil" if you want some ideas.
I have taken brand new shooters shooting and had them shooting the .45-70 the first day. My grandsons were shooting it and a S&W .500 at ages 13 and 14. When I am working with people and it is time to step up in caliber and energy I always have them watch someone else shooting that gun first so they know what to expect. We have all seen the YouTube of handing some unsuspecting new shooter a heavy recoiling gun which then hits them in the head or jumps out of their hands because they weren't "expecting" the recoil.
I have never had the chance to shoot a .600 Nitro or a .577 Tyrannosaur but I look forward to it.
I'll pass. I may get better with time, but my comfort level ends at about a .308 out of my 8lb (with scope) bolt action hunting rifle. So long as I don't fugger up I can handle an easy 40-50rnds in a session with at most a mildly sore shoulder the next day (from the bench, easier off hand. A lot easier).
I can shoot heavier recoiling rounds off the bench, but I don't like it. About as heavy as I am looking is maybe a .338 federal, but I'll probably go with something around a 10lb platform to help tame things some.