I don't mean to just jump in, but I hunted with the Remingtom 1187 up until two years ago (gave it to my nephew). I always used just the factory full choke, and harvested every bird I put it on. However, I agree with some of the other folks that an aftermarket choke tube is best, and worth the cost. It sure beats biting into copper when you decide to eat that bird. Where did you get a 21" 1187, I thought the shortest barrel length was 26", and is that legal where your from, not to mention shot pattern out of a 21" barrel. Just curious!