Avid----I have a m-2 with 21" bbl.---last friday I went to range with some 3" remington HD BB's. What I found was choke .695" pattern to lose---.675" choke pattern to lose but .685" choke had a high density pattern in 15" circle.
I use trulock extended hunter choke tubes the best that I have found----As a general rule I can NOT get tight turkey chokes to pattern good for my guns!
I have also found that I can reload better shells than I can buy, seems like magnums or horsepower the more the better----Not soooooo most a lot of waste. Just my experience.
I would try the 3" more than the 3.5" unless you go to 10 guage, trying to stuff alll that shot down the bbl. at high speed just can not be good!
