I had a 7.5" .454 SRH for years. Properly stoked, it would get your attention. A friend at the range got a BFR in .45-70... it made my arm ache... something that .454 SRH never did. Anyone who shoots a cylinderfull in a BFR .45-70 will have an aching arm... not from recoil, of course. Read Magnum Research's literature re the recoil energy of it vs many other more 'common' thumpers - or just do the math... it is relatively mild. Why, you say? The BFR .45-70 weighs a ton - and it is all out in front of your grip, tending to twist your arm off. The kick, at least with 300 & 405gr 'Govt' loads, isn't bad. It is a real 'blast' to shoot... and those big cartridges are just neat.
The absolute worst thing I have shot is a .50AE DEII, not because of it's recoil - but because of the way it is delivered. After the initial blast, you have a slight delay before the bolt/slide reaches it's rearward limit and the twist attempts to wring your wrist. Reaping the rewards of years of abuse, ie, CTS, my wrist prefers the kick of the .454 SRH far more than the 'thud-twist' of the .50 AE DEII. My arm shivers at the sight of the BFR .45-70... all said, I prefer my .45 ACP/Colts and .44 Ruskies & Specials these days...
Stainz