50 CAL is the largest I've shot. The worst has to be a large Weatherby 460 (?, I was young, the gun belonged to my uncle, and was the worst recoil I can remember).
I have a modern 1886 in 45-70. Due to the stock &/or butt shape, it becomes uncomfortable to shoot large amounts of ammo (20 seems plenty but who ever stops there).
Conversely, I have a rather well made 30-06 with a steel butt plate that has little felt recoil, I'd say about the same as a 220 swift in a Ruger #1. I've concluded the rifle template/design has more to do with felt recoil than CAL. JMO.
