I have a steel patterning plate of my own for checking regulation and patterns with my guns. I own numerous guns that have original constrictions tighter than .040", and every one of them patterns nicely ........... with the loads I use in them. Actually, I've never found a load that delivers blown patterns out of them. I tend to stay under 1200 fps, if possible, but not always........ BOSS bismuth loads pattern beautifully out of my L C Smith 3E and my A H Fox HE, both of which have chokes in mid-to-upper 40 thousandths range. When you kill six big ducks with six shells, and .048" choke, a couple of them long shots, your patterns can't be that bad.
