I'm pretty used to hard recoiling revolvers, so take this with a grain of salt...

I've not shot the .454Cassul in a contender, only in a Ruger Super Blackhawk...Mine wasn't that bad, it was on par with my BFR .45-70, but I think that had more to do with the size of the BFR and the hogue grips on it....I've shot a .45-70 contender, and it did kick a bit more than the revolver, but I don't think the .454 would be as bad.

Neither of them are going to be hard recoilers...I traded my .454 off for a Dan Wesson .445 Supermag. I've also ran a .475Line, .45-70BFR, and a Desert Eagle .50ae (ok, not as powerful as the others, but about on par with the .454), so the .454 isn't really much gun standing beside those hitters, but it's still a pretty potent gun.