A nice lace-up butt pad should do the trick and look good doing it.
Mine's an old 1978 vingage Marlin and I shot 265g cast out of it @ 1700fps at the muzzle, so far no big whoop.
I shot a newer one in stainless and I'd have to say it kicked pretty hard.
Odd when you consider the new one had a soft butt pad and mine has the hard plastic, who knows?
I bought an 1895 45-70 and recently got my mould for a 350g bullet over the weekend, so I'm going to try some of those out at 1400 and 1800fps this week. Never shot a 45-70, so this should be educational.