I use a load that would be very good for your friend, almost negligible recoil (virtually none) and very accurate in my Cowboy....but it takes a bit of messing around to have the bullet component available.
I powder coat 200-250 gr. .452 pistol bullets up to .460 (two or three coats of powder depending on what powder I use) and then size to .459. I load these slugs up in front of 26 gr of 5744.
two ways to acquire usable bullets...buy wax lubed commercial hard cast from local gun store and boil the wax off , after boiling , swish in a small amount of methyl hydrate (I use common gas line antifreeze). They must be absolutely clean of any residue for the powder coating to stick.
The other way is if you know a commercial bullet manuf that will cast a bunch of .452 slugs for you and sell them to you unisized & not waxed...this is the best& easiest.