More on the SIG ACP “Adaptive Carbine Platform”

I have good news. SIG will be selling the law enforcement /folding stock version of the SIG ACP to consumers through commercial dealers. Any pistol used with it will still need to be registered as a Short Barreled Rifle with the BATFE.

There are five models (although only three were listed in the press release) …

The ACP – Standard which comes with the universal pistol adapter unit with QD sling mount and mounting hardware for the end user’s pistol.

The ACP – Enhanced which comes with the Standard unit, a single point bungee sling and a Mil Grade Mini Red Dot Sight.

The ACP – Law Enforcement which comes as the Standard unit with a folding stock. This will be available commercially through dealers. All NFA Rules apply.

The ACP – CPL which comes as the Standard unit with a single point bungee sling and a compact laser aiming unit.

The ACP – ZK which comes as the Standard unit outfitted with the compact laser aiming unit, single point bungee sling and a molded zipper case.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • I’d much rather see a proper carbine made for the 22X platforms. Not a big fan of Kel-tec myself. I think most people will agree with me. It would be easier and simply less trouble that have to deal with the ATF.

  • Dave D

    Fail! I don’t know what Sig was thinking with this one. I can understand some of the other “carbine type” pistol conversions on the market and actually liked the CAA Glock “carbine” I shot at the demo last year. Sig fails here by suggesting that without a stock this is an improvement to the pistol. There is nothing this can do that the pistol without this could do. More importantly the pistol without the ACP can do it BETTER. Less bulk, more reliable, standard malfunction drills, and less likely to jam.

  • George

    What exactly is the purpose of this? It looks pretty sweet, but you can mount a red dot directly to the slide of a pistol and have a smaller package that does the same thing.

    • Other Steve

      In case you need your handgun to be heavier and harder to hold, maybe you want it to be less concealable? Perhaps you have too much money on your hands?

      Really not sure how this is could be better than a quality gun with a red dot.

  • West

    This version, without fore-grip and stock, is even more pointless.
    Who would want to pay several hundred bucks to add weight, decrease accuracy and deal with a mountain of paperwork just to carry their Glock on a sling?

    I think ill just tie a string through the trigger guard and wear it around my neck. Tactical and practical.

    • Ken

      Be careful, West. A shoelace is considered a machine gun… 🙂

      • West

        Ken, in the above pics it looks just like the blasters carried by the Imperial Stormtroopers in Star Wars.

      • Komrad

        Those were Sterling submachine guns with some fancy spacey looking stuff added. Han Solo’s DL-44 blaster was a C96. E-Webs were MG-34s. The light repeating blasters carried by desert troopers were Lewis guns. Clone blasters in the prequel trilogy were two Sterlings stuck together. Leia’s sporting blaster that she uses on the Tantive IV in episode IV was some target pistol.

        Lucas actually used a lot of real (and functional) firearms in Star Wars.

      • W

        komrad, you intrigued me to do some research into that matter and needless to say im shocked. I never watched the Star Wars Trilogy, though you inspired me to watch the first one and i laughed my ass off because it reminded me of your post. LOL

      • JonMac

        Not quite. The clone blasters were new designs incorporating elements of the MG34 and Sterling.

        Leia’s blaster was a Vostok Margolin – I had to check IMFDB for that one.

    • Patrick

      Actually, Glocks already have a hole for a lanyard loop. No need to compromise your trigger guard area.

    • Cymond

      First, there’s no ‘mountain of paperwork’ unless you’re using a stock or foregrip which requires SBR/AOW registration. Second, SBR paperwork is about 4 pages, so not exactly a ‘mountain’.

  • Spade

    I’m curious as to why the one in the pictures needs to be an SBR. There’s no stock, just a sling. Just like a B&T TP9 or a HK SP89.

    • Ken

      I don’t believe the one in the pictures will need to be considered an SBR. Only putting the stock on there will make a tax stamp necessary.

      “The ACP – Law Enforcement which comes as the Standard unit with a folding stock. This will be available commercially through dealers. All NFA Rules apply.”

  • Other Steve

    I used my TP9 and MP5 as pistols while waiting for the SBR stamps to come…. Most pointless, heavy, cumbersome, inaccurate “pistols” I’ve ever used. I have zero interest in a TP9 pistol, but as an sbr it kicks ass.

    Unless you SBR the gun and get the stock and foregrip this is absolute idiocy.

    The idea that adding a big aluminum chassis and a red dot will make your pistol better somehow is really reaching.

    I can’t believe SIG’s marketing agreed to this.

  • Other Steve

    ALSO… I just noticed the abondance of top rail space… WTF. Is anyone going to run BUIS or night vision on this thing?

    I’ve changed my opinion from ODD to FAIL.

  • Rangefinder

    Is Sig providing a thigh, shoulder, or chest holster for this system? It would be nice if the pistol could be locked into the system one handed (quick mount) while the system is holstered separate from the pistol.

  • Lance

    Looks fun how much is one and what pistols are they for again??

    • Other Steve

      You know damn well it’s UNIVERSAL. You commented on yesterday’s article that discusses that in detail. You wrote how it would be cool for a 92FS. For some reason. It’s expalined in the video, etc etc.

      So that’s it, you troll the firearmblog not reading the articles and just posting questions that make no sense?

      • Ken

        We have to accept the possibility that the internet is full of people who aren’t very sharp, and have thin reading comprehension skills.

        To do otherwise is to be trolled by everyone.

  • Matt G.


    • Other Steve

      $500 or so.

      Not even close to worth it. The only practical application this thing comes close to is a practical joke. IMO.

  • Brandon

    For the buttstock version, you’d have to register the handgun as an SBR, no the ACP chassis. So you’d be limited to using one handgun in it (unless you paid $200 stamps for each) So much for universal

  • BKern

    Here is a question. If you were to own the stocked version, and registered one of your railed pistols as an SBR, would the BATFE hold you liable for possessing and unregistered SBR if you own other railed pistols that you had not registered for use in the stock? Just asking.

    • Tango Down

      First off, I am NOT a lawyer nor do I have expertise in this area.

      From my understanding, when I pursued this same query in reference to the RONI unit; IF you purchase one of these types of units that require a $200 tax stamp to own and use, you also “link” your pistol to that apparatus. Not only is that weapon “linked” to that apparatus, you can not sell that gun, even without the apparatus, to ANYONE unless they have a tax stamp to own it. This would mean, according to my research, that if I bought this for my SIG Mk25 and got the legal paperwork completed on it, that my Mk25 would be considered a SBR because it’s listed on the paperwork, additionally, I couldn’t ever sell my Mk25 in private transaction becasue of this paperwork, like I could otherwise.

      If this information is correct then I’d have to say that it’s definitely NOT worth getting the version that equips the stock. I’d just get a straight SBR.

  • gunfighter2012

    Could I get some cheese with this whine?

  • DB Cooper

    Sig is getting desperate. This looks alot like one of those CAA Roni kits.

    • Tango Down

      While I can see your point about them resembling the RONI, these are far more sturdy built, being that these are made from metal, unlike the RONI, which is a snap apart plastic rig. As for it it’s really of any true benefit, that I can’t answer. Is it really worth another $200 for a tax stamp to get the version with a stock, NO! If you’re going to go that route, just get the SIG 516 Patrol SBR instead!

  • North

    How can I get the version without the stock in Massachusetts?

  • Hey, thanks for the blog article.Thanks Again. Great.

  • Weez

    When are the ‘non-stock’ versions going to be available?

  • reiko

    why would you ever want the hassle of a SBR for that? I just don’t see the need for a stock or that many rails on a pistol.. just buy a subgun if that’s what you want, or is this supposed to be the cheaper way? Just put a stock and a extended mag on a pistol and there’s your subgun??

  • Motorsam

    As a motor officer I look forward to having a second weapon with some versatility. Currently I have a .45 1911. And that is it. Because of the newer bikes out storage area is limited for short barrel shotguns, rifles are problematic as well. I se as just am enthusiast this would not make a lot of since, but it is worth a try for the working group.

  • allanonmage

    This is really cool. I saw one at my local gun shop yesterday. They wanted $369 for it. It’s really overprices, which makes me sad. Once you buy all the parts it’s crazy expensive:

    ~$500 for a pistol, $500? for the sig kit with the stock, $200 tax stamp, $400 optic, $500? for a silencer, $200 for THAT tax stamp…. $1600 – $2200 for a really cool looking SBR that’s on par with a Kel Tec Sub2000 that costs less than $400….

    If I had an unlimited budget, I’d get all that stuff and play with it no doubt. If you add in a silencer or barrel extension though it’s the same size as a regular rifle and you’d be better off buying a carbine though.

    It’s still REALLY cool….

    • Tango Down

      I can’t help but wonder where you found a new SIG for just $500? *LOL*

      • allanonmage

        $500 (ish) seems to be the low end of the ballpark for pistols in my area. No idea if Sig’s fall around there, I mostly look at the Glock and M&P’s.