Ok guys, don't kill me for asking this Q... I've nver owned a shot gun. I'm looking at 12 GA's right now... I went to Sports Authority and checked out 2 pumps... the 870 and a winny. How do the chockes attatch to the barrel? I didn't see any threads inside or out on the barrel? Also, I'm looking at making it a skeet/deer shot gun. I wasn't overly excited about the 870 when I held it.