More Gun Blegging: Pistol Caliber ARs

I’ve never been into pistol caliber carbines all that much. I’d be interested in submachine guns if they were legal, but semi-auto pistol carbines have just never tickled my fancy. However, my club has steel targets set closer than 100 yards that are limited to pistol calibers, and our indoor range is limited to pistol calibers. We’re also about to get more pistol-caliber-only steel. So I’m thinking a pistol caliber AR-like carbine is something I could use.

But I’m not sure what to get. I’m not opposed to registering it as an SBR, and as long as I’m doing that I might as well register a can for it. To me a 16″ barrel on a pistol caliber gun is a bit pointless. But maybe I can get a pinned or integral suppressor that takes it out to 16″ and only need one tax stamp? To me if you’re going the suppressed route, the .45 ACP is a better option, but I believe that takes a more AR-10 sized lower. One thing for sure is I’d want it to take Glock magazines.

Anyone out there have any experience in this area?

38 thoughts on “More Gun Blegging: Pistol Caliber ARs”

  1. 9mm subsonic (pretty much any 147 gr load) suppresses better than .45 ACP, and is cheaper per-round too. Unless you already have pistol suppressors I’d advise not getting a permanently attached suppressor. More than likely you’ll kick yourself later for not retaining the ability to move it to a different gun.

  2. Most of the “standard” pistol caliber uppers are available for the AR15 pattern. That includes 9mm, .45 and 10mm. Throw in some of the stuff from KAK, Taccom or Deadfoot Arms & it can get interesting. AR pistols are a thing. (yes, 10mm. you’ll need to search a bit tho)

  3. When it comes down to the Pistol Caliber Carbine, nothing beats the M1 Carbine itself. The only PCR I have and will ever want.

      1. “Not pistol cartridge.”

        Except when used in a Ruger Super Blackhawk — an ear-splitter I’ll never forget.

        1. The range will not buy that argument, however, any more than that T/C Contender in .223 is “a pistol caliber”.

      2. It’s more of a pistol round than a rifle round, and it’s not exactly straight walled, it has a slight taper but no shoulder. Been loading them since the late 80’s :-)

  4. I’ve spent the last year, off and on, trying to find a good 45acp carbine wherein neither the rifle nor mags cost an arm and a leg. TNW, JRC, Macon Armory and NFA are the three names that have floated to the top of the list. I just can’t get a handle on if any of them are any good. Anybody got anything first hand? I’m particularly interested in NFA.

    1. I have a Macon Armory gas operated .45 upper. Barrel is 7.5″ and it runs like a top supressed or unsupressed. It’s an absolute blast to shoot. I use it on an older CNC Gunsmithing dedicated lower that takes Grease Gun mags. My only caveat is that the GG mags have no provision to lock the bolt back after the last round.

  5. Do a AR pistol with a brace. Any length barrel, and a dedicated 9mm lower for Glock mags. Not NFA.

    1. John here is correct, with the advent of the AR pistol brace, there’s really no reason to go SBR any more.

      1. You’ll need a shoulder stock if you want to compete in USPSA, IDPA or Steel Challenge PCC divisions, because they all specificly ban arm braces and require shoulder stocks.

  6. I have the JRC in .45ACP – it’s OK. Doesn’t feed particularly reliably. In the end, I wish I had bought one built on a standard AR-15 split upper/lower receiver – the JRC is a monolithic receiver. But I’m not so remorseful that I’m ready to sell it :)

    1. Had a JRC .45ACP for a bit, traded it when it kept breaking off ejectors. 3 in 4 months. No thank you.

  7. build a 9mm AR SBR last year and it is an absolute blast to shoot. obviously not the “best option” compared to other guns in X or Y scenario, but zero regrets.

    i admit the changes in trusts in 2016 may have largely motivated this build, however.

  8. I see two routes you could go.

    (1) Set up a great little pistol-caliber carbine in its own right, possibly SBR and/or suppress, and enjoy it as such.

    (2) Set up a 9mm duplicate of your 5.56mm carbine, with the same optic and accessories, and use it as a substitute for your 5.56mm AR for when you want to shoot close-range steel.

  9. Personally, I’d forgo the ar pistol Cal car in and just get a CZ Scorpion (full disclosure, I have both). The cz will suppress better and not blow back into your face. And they’re damn fun to shoot! Mags are cheap and it seems everyone and their brother is make aftermarket parts for it.

  10. I looked at an AR PCC. I decided instead to get the Scorpion. I was able to put an entire 30 round mag of 9mm into the 10 ring at 15 yards just as fast as I could pull the trigger.

    The downside is that the Scorpion doesn’t take anyone else’s mags. There are discount aftermarkets, though.

  11. Well, if looking at pistol caliber carbine, why not the 9mm Ruger PC Carbine? Yeah it’s not an AR, but it does use Glock magazines and it has other virtues too.

  12. TL;DR: Blowback PCCs suck. Avoid. (I don’t know why people put these at the bottom, seems like you only find them after reading everything)

    I don’t have a lot of experience with PCCs, but I did have some HKs (HK94, SP89), a 9mm AR, and an M11/9. The HKs were a blast. But the problem is if you do any real shooting with them, you’ll find yourself becoming a fully-stocked HK armorer. So unless you have lots of money and space you can’t figure out what to do with, I’d avoid.

    The 9mm AR and the M11/9 both suffered from being blowback monstrosities. Before spending a bunch of money on a blowback PCC from any manufacturer, I’d recommend trying one out if you can. Any blowback, not even necessarily the same one you’re thinking of buying. My experience is limited, but the difference between the blowback guns and the delayed-blowback HKs was night and day. The blowback guns are heavy and jerky and just felt clumsy and inelegant. I couldn’t stand shooting them. YMMV.

    Then Sig has their MPX which I haven’t tried but people seem to like. If the Sigs weren’t so expensive, in a perpetual beta test, and lacking parts and aftermarket support, they might be a good option.

    CMMG has their Guard “Radial Delayed Blowback” PCC system. I haven’t tried one, but it seems to be well received so far. I’ve seen it compared to the HK delayed blowback guns in terms of smoothness, but I couldn’t say. Since I have a bunch of AR stuff, that’s probably the direction I’d go.

    And there are plenty of AR-based options that use Glock mags. Or you could go this route when it’s available:

    That way all you’d need is the CMMG bolt, barrel, and some Endomags (and maybe a buffer or something) to be in business if you already have an AR and some PMAGs.

    RE: Scorpions – they’re blowback (see above), and do a websearch for mags cracking if you consider one.

    1. If you are putting a summary at the top, it’s a BLUF (bottom line up front).

      What’s wrong with blowback PCCs, specifically?

      1. What’s wrong with blowback PCCs, specifically?

        They’re heavy and bouncy, which negates some of the fun potential.

  13. Last year I put together an AR pistol in 9MM that uses Glockazines. I had a Vector Gen 2 but after figuring out that the weaker shooters that I like to take to the range couldn’t charge it, I sold it. I built up a side charging AR9 using a New Frontier Armory receiver set, Law Tactical folding adapter, an 8 inch barrel and a 3 lug for my suppressor. It’s nothing more than range toy but its a boat load of fun. It doesn’t seem to like rounds with a flat nose. I highly recommend a pistol setup for a PCC for fun.

  14. Years ago Cavalry Arms had an all-plastic AR receiver that would accept grease gun mags with an adapter from Brownells.

    When Cav Arms went bust, the tooling was sold to somebody else, and then they went broke, and I lost track.

    They made plenty of receivers – maybe there’s one around.

    Together with an Olympic 45 upper, and you’re in business.

    It’s not suppressed or SBR or anything, but it’s a start.

  15. Put down the sissy ARs and get a Mac10 and be done with it. PCC are the 6.8 of 2018. They’ll be cool for a year or 2 and we’ll move on to some thing else and you’ll find it one day collecting dust in your safe thinking to your self “Self, why did I get this…? “

    300 b/o with a binary trigger.
    or, just get a Mac10 and don’t look back. Heck, with the double size Grease gun mags I can hold a mag dump for just between 4-5 seconds ( 68 rounds )

    1. “Hi, I’m looking for something as heavy as an AR-15, but not nearly as configurable and definitely not as ergonomic, and I’d like a crappy open-bolt operating system and it should bounce all over the place as I shoot. Oh, and I should be tied to about one caliber and the gun should cost 10x as much as an AR too. What can you recommend?”

      1. BINGO!
        It’s stunning just how bad the MAC is when compared to any other subguns in their class. They would be the LAST gun I would pick up from a pile on the floor. Convert it to semi? Please, an original GM Liberator pistol would be better.

  16. Built some pistol caliber Ar’s off quarter circle 10 lowers but for the money might as well get a cz scorpion with a brace.

  17. If you’re shooting steel, .45 wallops the targets a little more satisfactorily. The Direct Impingement gas op conversions are A LOT more comfortable to shoot than the blowback ones. I’ve owned both, but DI is the one I kept.

    Do you already have a registered SBR? If so, the Macon Armory gas-op conversion kit is a good turn-key option. Comes with 8″ barrel, magwell conversion block, and two 20-rd magazines. Special mags, but they work with a standard lower and it’ll save you another tax-stamp.

    If you absolutely want to use glock mags, contact Rudy at Macon Armory. He’s a great guy to work with and can probably point you in the direction of a lower known to work with his DI upper.

  18. If you’re going to suppress it… you probably don’t want an AR in 9mm. And 45 is a flat out no.

    Try the CMMG Guard which is delayed blowback.

    The MP5 clones are the best suppress-able guns out there,

    If you really want AR platform, shoot a few suppressed first.

  19. The AR PCC, even in 16 inch, are great fun. Is suggest getting an inexpensive PSA with a Glock compatible lower and just enjoy it.

  20. I built an integrally 45 ACP AR over 10 years ago and overall I would not recommend this approach anymore.

    The main problem with 45 ACP is that there are no widely available magazines that will fit in a standard size magwell. I ended up using a lower that fit grease gun magazines, but I get no last round bolt hold open and the mag release is under the magwell.

    Although I never got one, I am kind of partial to 300 BLK because it mostly replicates the ballistics of 45 acp and everything works in standard magazines. Dunno if subsonic 300 BLK counts as a handgun caliber though. No idea if terminal ballistics are comparable either. 45 does make a big hole every time.

  21. I built and regularly shoot a Glock mag 9mm AR and I love it. I used the New Frontier upper and lower with an 8 1/2″ Faxon barrel and a 9″ Aero Precision handguard. I regularly shoot it with my Thompson Machine ISIS-2 and it works well with both 147 and 158 grain subs, I use a 2 1/2″ long flash can as a thread protector when not shooting suppressed. My two suggestions would be to go with a side charging upper (the New Frontier type is VERY nice) which is sealed at the rear which eliminates blowback in your face, and get the absolute heaviest buffer you can find which really smooths out the recoil. I use a Kaw Valley Precision 10oz. Extended Tungsten buffer which avoids having to insert a spacer in the buffer tube also.

  22. I have a Spike’s Tactical dedicated 9mm lower that accepts Glock 17 magazines. I have a no-frills AR Stoner 16 inch M4 pattern upper on it I got on sale at Midway. The pairing works once you tweak the ejector on the lower as it rides too high and binds on the bolt carrier causing failure to feed with a magazine in place. Drive out the roll pin, lower the ejector and bend it just a bit to the left and the problem is solved.

    I built it as a $450 experiment and it shares mags with my Kel-Tec Sub-2K and Glock 17. Only catch is the lower is fussy and tight on magazines. Factory Glock magazines work fine, either 17 or 33 rounds. Magpuls fit but really need to be persuaded into the well. The mag catch is just a wee bit off.

    If working to get an upper to run with a lower is an issue, I’d just buy a dedicated 9mm rifle that accepts Glock magazines. I’ve found the 9mm rifles are not the plug-and-play items like the 5.56mm guns are. You need to choose between magwell block vs. dedicated, Glock or Colt and choosing the appropriate BCG (Glock-specific, Colt-specific or universal).

    I would have preferred a .45ACP upper but those really never took off. Olympic Arms made a .45ACP carbine at one time and they were iffy from what I’ve read.

  23. This thread interests me because I have an irrational attraction to PCCs; and might consider an AR-15 (rifle-size) build for one that took Glock 17 mags.

  24. There are so many pistol brace/buffer tube options nowadays that you don’t have to worry about registering it as an SBR right away.

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