an 8 bore loaded with a round ball and 250 gr of black powder was fairly rough. Though I think I could eventually get used to shooting it. Now the .577 Nitro - one shot made my teeth hurt.
No!
I have a Ruger #1 in .475 Turnbull, which is a fairly light rifle, given its C barrel contour. with scope it's only a hair over 9 lbs, and can be loaded close to a .470 Nitro.
So I think my recoil limit is probably somewhere north of a .470 Nitro, and south of a .577
