I have several shotguns from 12 ga. to 410 bore. I have a 20 ga that I like to use for squirrel hunting it is a full choke I also own a 28 guage with a modified choke. Using a choke guage the 20 comes in at a heavy full the 28 guage hits the same mark making it a light improved cylinder. My question/problem is why I can kill squirrels farther away with the 28ga. I consistently take them at 40 yards plus but have trouble at that distance with the 20. I have paternd both and the patterns are similar to 40 yards. This makes no sense to me.