Zeprin
I don't see any reason why it can't be done , kinda like a 38 spl in a 357 mag only bigger , that being said with the price of 45/60 brass why would you not just shoot 45/70s ?
It can be loaded very low with Unique or Trail Boss to bring the recoil and report down to that of a 410 shotgun and no filler required .
With Black powder that would be another story , wear if you were going to shoot many rounds for a CB Shoot it may be a little easer on the sholder .
stimpy