This is the best explanation I have read, regarding the "Recoil Impulse, Velocity of Recoil, and Energy of recoil. The "Moment of Recoil, Rifle Balance and Recoil Speed makes a lot of difference for a slight framed (skinny) guy like me.
I read some years ago, that a British Ordinance Officer (can't remember his name), that claimed most men can shoot a rifle comfortably up to 17 Pounds Feet/ Second of Recoil Velocity.
I think this applies for medium bores as well, as many shooters feel the sharp recoil effect of Weatherby Ammo. Almost all are greater than the 17 pounds feet per second level.
When I ran the numbers on a .416 Rigby (410 grains at 2350 fps) and a downloaded .416 Remington (400 grains at 2150, old school Nitro Express), it made a lot of sense.
The 400 grain at 2150 was right at 17 pounds feet per second recoil velocity, and I can shoot this accurately for several rounds.
The .416 Rigby, 2350 fps was about 19 pounds feet per second, too much for me to shoot accurately after 3 shots.
That's why I shoot a 450/400 Nitro.
But I really want a .404 Jeffery, for the nostalgia factor.