I shoot an 835 with the choke that came with the gun. The choke extends 3/8 in. past the barrel and has .675 stamped on it. This gun likes the Win. Supreme High Velocity 3 1/2 in. 2oz. #4' s. The average pattern is 110 in a 10 in. circle, with 40 hits in the head and neck and 16 in the critical zone at a measured 40 yards. I shot it at 50 yards a couple times and a got around 18 in the head and neck with 6-7 in the brain and spine.