3" .460 yikes.

The 5 or 6" .500 S&W magnum I shot last summer with 325gr. factory ammo, kicked less than my round-butt grips on the M29 4" using max. 300gr. TC commercial cast, max. load W/H110.

I think the big gun and a decent round with 4 or 5"lb max. would be perfect.

I find the long barrels have a bit too much muzzle flip for quick recovery. The 4" M29 with full sized, smoothed grips excels at quick recovery, in comparison that is.