Hello Seth07

I have a comp n choke in my 835 mossberg. I installed it about four years a go and I am not disapointed at all. My choke will put a 2 inch hole in paper at 20 yards using 6 shot. The constriction on my choke is .670. The constrictions Comp n choke offer vary by gun. .670 is the tightest constriction they make for my Mossberg. They offer tighter constrictions of .665 for some brands of shot guns. You can over choke a gun, Tighter is not allways better. Here are a couple of links to help you out

Jerry

http://www.midwestturkeycall.com/pro...ries&dn=1&cc=T

http://www.comp-n-choke.com