I still have no personal experience with the KSG other than handling one at my last shotgun class (Awerbuck), back in Sept. last year. Here's what I noted at the time fwiw:
The KSG was interesting, the first one I've seen for real. I'd say is just too complex for most folks, especially those already accustomed to other shotguns. Not just IMHO, but Louis thinks so too, and he's shot one (I haven't, I just watched when I could in class). Too many controls, too many options (two magazine tubes and a magazine selector to choose between them), just too much to keep track of under pressure. And mainly, the worst thumbs down of all for me from the getgo, it's too hard to load on the fly, since it's a bullpup and the loading port is behind the pistol grip. I had a bullpup for years, a semiauto at that, a High Standard 10-A. Sold it, but bought another example a couple of years ago. Great shotgun - for five rounds. Then forget it, dump it and go to something else.
Same deal with the KSG - if your gunfight is shorter than 15 rounds, and you can remember how to run the gun through a mag change without something bad happening, you're golden. --
http://www.thehighroad.org/showthread.php?t=676207
The KSG I saw in a fellow student's hands was still fairly new to him, IIRC he said he'd put 200-300 rounds through it before the class. While it didn't give him any trouble as far as reliability was concerned, it was a hassle setting up the ammo load for the different drills as they were called. As indicated earlier, if the ammo load is set up as you're willing and able to use it it the outset, and your gunfight is short enough, it will do.
As for me, I can empty six or seven rounds out of a conventional pump in less time than it takes to tell it, and being able to keep the gun fed on the fly is critical as far as I'm concerned. And that's the downfall of the KSG in my stodgy old eyes. It's just too hard to load quickly. I'm of the "no magazine is ever big enough" school, I'm biased in that regard and perfectly willing to admit it. I want a fighting shotgun that's easier to load as required, even if only one round at the time.
The KSG definitely has advantages, its shortness being chief among them. The student referred to here had bought his KSG with the intent of using it as a defensive shotgun on his boat, and it should be useful in that role. He also planned to keep it loaded with slugs, which would simplify the ammo hassle for him. And as with any other shotgun, it takes trigger time to learn the controls on a new shotgun and 'groove' their use. That's no small investment in time, effort and ammunition, but it's one a serious user will be willing to make.
Learning to use the magazine selector with its center cutoff position shouldn't be that big a deal, and learning the sequence when running one tube empty shouldn't be a big deal either once operation of the shotgun becomes reflexive. A CLICK on an empty chamber in the KSG is followed by SWITCH TUBES then by ACTION RELEASE and PUMP to load a round from the second tube. That's not impossible to learn, just ... different. And it was different enough to flummox this student from time to time in class - because he had not yet had time to really learn to run the shotgun at an instinctive lesson. He didn't let it get to him however, and soldiered on with it in the face of Louis continuing to bark instructions.
I didn't get to take any of Louis' classes in either of his two 2013 visits to NC, unfortunately, and therefore didn't see this student (who is a regular in Louis' classes) this year to ask him about the KSG and how he's doing with it.
I'm looking forward to seeing a new generation of shooters out there using the KSG and other contemporary evolutions of the fighting shotgun. It's definitely going to be interesting, even if I'm too old a dog to try and learn new tricks
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