A good friend has one with the 10 gauge bbl bored to 12 and rifled.He likes it greatly.
The trigger's heavy but clean. Since these are H*!! to take apart,I'd check the pull first, then maybe buy a shoe.
His is quite muzzle heavy, a good stand gun but a bit awkward for still hunting.
A couple of decades ago I had an H&R Huntsman, an inline ML built on that same break action frame. A 58 caliber,it shot well with a .570 round ball, a Butler Creek egg cup sabot and 80 gr of 3F. This took a couple meat deer for me and cleaned up fast for a ML. There was a downside...
The down side was that if the cap were not fully seated on the nipple, it could get pinched between the standing breech and the nipple, firing the cap.