I have shot probably 300 rounds of 1 oz and 1 1/8 oz shot loads through it at sporting clays.
Both barrels provide a decent modified pattern with 7 1/2s and 8s. I would have expected the rifling to act like a dispersion choke but it does not.
I have not done anything with bullets. I suppose Ross's load of Unique would be ok, but it sounds like an awfully fast powder for such a heavy bullet.
I am cautious with it because it is not all that common and purchased from a good friend - so it has a sort of talisman like quality for me.
I see a lot out there loadwise in the literature but I worry about pressure.
Worst case scenario I will make up a pliers like "fixer" to put a crimp all around the hull into the groove of the slug and use black. If the bullet protrudes a bit out of the case, that is ok by me.
I think that with black and a very soft slug I will not get in trouble and see if it comes anywhere close to regulation.