I'm dealing with the same issue on a couple tight-choked old European 12 bores. It's tempting to specify a desired constriction, take it to a competent chokemeister and call it good. But the fact is that while both guns do seem to be choked tight, right now I have no idea how tight and how much difference specific loads--spreaders, etc,--make. So I'm back to the advice that appears so frequently on this and other boards. I need to pattern my guns! Back when I lived in bear country, I scoped my 30.06 in at least once, sometimes twice, each year. But I've never patterned one of my own shotguns. Pretty sorry, but maybe not that uncommon.
