Anyone have a 20 ga factory choke and decent caliper to measure the constriction? I asked the factory and they said it is a .575, but my caliper only goes 2 decimals and shows .56. I would expect it to read .57 if what thd Stoeger rep told me was correct, and I'm thinking it is a .565 or .562. I'm looking to get a better brand choke in the same constriction since the factory choke gives a better 40 yd pattern than the Carlson .555. Thanks in advance!
I have the stoeger in a 26" barrel land use a Sumtoy .562 with good results. I am shooting #9 federal TSS. Killed 2 with this combo last season.
Factory extended choke that came with my M3020 miced. 569" and it actually shot very well with Apex GT20 3"/1 5/8oz./9s . What choke you use will really depend on which shell you're shooting. But IC is certainly a great choice, along with JEBs, Carlsons' and one that really does good out of that gun is the Primos Tightwad .570 which can be had for usually around $20 or so. Good luck!
And I might add...not sure if it's exclusive to all or most M3020s but mine seems to perform better with a more open choke.