The easiest way to tell is by the selector switch for the feed tubes. Chad from Kel-Tec gives an introductory video of the KSG with info on upgrades and some. If you own a KSG shotgun you know that there is a series of numbers and letters instead of a. As my gun will be used in a climate that can only be described as "soggy" I am very thankful for this. I got my KSG today, and I would like to know the manufacture date. Other improvements to the KSG on the 2nd generation include a trigger reset, small shell tube peep holes, and a fix of the action release to be easier to use and.