I took just under 1k scratch phez over years with a Mossberg 500 12 with a cyl choke tube. Later I was able to determine the constriction was, factually, .000. Worked to 25 yds any presentation, out to 35 yds on incomers. Crossers somewhere in the middle.
Most always I used Remington 3 dr #7.5 trap loads. I mention this b/c there is no way to approximate this performance with a subgauge with .000. I tried many different brands. The pattern board tells the story. Mostly, it's about payload and quality of best factory traploads. The rest is efficiency of the larger bore diameter.....I guess.
Have never played with a cyl 16 - maybe that would work. I know my cyl 20 and 28 are not good enough for anything but the 1st week of Oct on WC/grouse. If I use 1 oz B&Ps 20-22 yd shots are a very safe bet. I would never take them out for even planted phez.
However considered as a wordsmith, McIntosh was imprecise. He'd speak of "lightly constricted" as equivalent to "no choke at all" - whatever the heck either of those expressions mean. Well, the difference on paper between 12s with .000 and .005 is greater than the difference between 12s with .025 and .040. I think a 12 with a .005 bbl is very sensible. It's not that I won't get as many birds with a .015 1st bbl. I don't want to burgerize them.
Sam
