Gun Review: Quarter Circle 10 AR Pistol in .45ACP

QC10 45ACP (image courtesy of JWT for

I was wrong. But I can change. If I have to. I guess. My days of bewilderment over the pistol caliber AR are over. The Quarter Circle 10 in .45 ACP opened my eyes . . .

First off, yes, this is legally a pistol. The QC10 GLF .45ACP comes equipped with a custom SB Tactical Brace. Stock? If the SB Tactical Brace is a stock, it’s a crappy one –at least on a gun where a cheek-stock-weld is important. In fact, when I picked-up the QC10, I thought “if I was buying this gun, I’d convert it to an SBR ASAP.

After shooting it, I changed my mind.

Chambered in 45ACP, the QC10 GLF  doesn’t generate enough recoil to matter. The brace stays in place no matter where you put it: arm, chest, shoulder or belly button (really, I have no idea what kids do these days). Top it with a red dot optic — as almost everyone using the gun will — and your cheek-stock-weld isn’t nearly as important as it would be if your were looking through a magnified optic or iron sights.

This QC10’s SB Tactical Brace is bespoke and branded. There’s no guessing on the buffer weight or spring. It works perfectly; there’s no reason to change it.

Part of the reason this gun carried so well and ran so well: it’s not an AR modified to fire a pistol caliber cartridge. Quarter Circle 10 prides themselves on being THE Pistol AR company. Receiver, bolt, barrel, brace — everything is built from the ground up as a pistol, using pistol caliber parts, many manufactured in-house.

This particular model is a made for GLOCK 21 (.45ACP) magazines.  Want one for a GLOCK 9mm?  They’ve got that.  .40S&W or .357Sig?  Yup.  Extended Metalform SMG 1911 magazines? Yup yet again.  Plus multiple barrel lengths, hand guard lengths, brace and stocks.

If you like the ergonomics of an AR rifle, you’ll like the QC10 as well. It’s exactly the same.

The QC10 pistol grip is the same mil-spec grip you see on so many rifles. It works for many people, but I hate it. The finger groove hits me in exactly the wrong place.  The safety is the familiar two-position toggle. After a few quick ups and downs, it moved easily with a solid start and stop. The bolt lock/release is slightly recessed into the upper receiver — just enough to get out of the way. It responds immediately to a thumb press or the more likely palm slap.

Thankfully, QC10 chose not to follow in the misguided footsteps of so many other manufacturers with a standard mil-spec type charging handle. A larger latch comes standard, making fast charging with your left hand quick and easy.

This is especially valuable in the case of a malfunction. Considering that many of these guns are built with self defense in mind, the speed of your TapRackBang may mean the difference between life and death. QC10 got it right. Plus, the bolt holds open on an empty magazine. Every time.

The hand guard is completely functional. Our T&E gun came equipped with KeyMod. It ends just shy of the 7 1/2″ barrel and includes a QD sling mount on either side near the receiver. Other barrel lengths and matching hand guards are available.

Aesthetically, the lines of the upper receiver and the hand guard don’t quite flow together. It doesn’t look like they were designed to.

Another nit-picking critique: the finish.

Everything on the rifle is finished smoothly and evenly. But the anodizing on the upper and lower receivers don’t quite match. They’re close, and you can’t even tell one is slightly shinier than the other except in certain light, but the difference is there. I’ve found the only way to get consistent anodizing is to have both the lowers and uppers done in the same batch at the same time. Or just cerakote over it like a lot of AR makers do.

Although the QC10’s trigger is a solid meh it’s one of the better “mil-spec” types around. It broke at 5lbs, with a bit grit and stack prior to the break. I’d like to see Quarter Circle 10 offer a factory-installed trigger upgrade. A light and fast single-stage trigger with a flat shoe would be the bees knees on this gun.  Of course, if you want one, this accepts standard AR replacements like the ones made by a dozen different companies.

The magazine release may look different, but it feels just the same. A quick push of my index finger and the GLOCK magazines dropped free  Inserting the GLOCK magazine was just as easy, with the pistol’s flared and funneled magazine well. Quick ammunition changes are a breeze, and they’ll need to be.  Standard 13 round GLOCK 21 magazines aren’t likely to go far at the rate of fire you can push through the gun. And if you’re like me, you’ll want to.

At first I had some issues with reliability.

Using a 230gr FMJ round nosed bullet I experienced a few double feeds during my first few magazines. I used the malfunctions for failure and transition drills with my GLOCK 21SF (review pending). I ended up doing a lot more malfunction drills than transition drills; the G21 had the exact same problem. The brand new 13 round GLOCK magazines apparently needed some break-in time.  I didn’t have a firearm issue, I had a magazine issue.

After that initial break-in, the QC10 ran perfectly. And I mean perfectly with EVERYTHING.  I shot Winchester White Box FMJs, Armscor 230gr JHPs, Winchester PDX1 Defender 230gr HP, Remington Ultimate Defense 230gr HPs, Hornady 185gr FTX, and my own handloads in multiple weights and different types of jacketed and LSWC rounds. I even ran some decades old rat-shot through the thing (big donut pattern, completely worthless).

I had no problems with the gun at all.  I usually put 500 rounds through any semi-automatic for a review. The round count on this one hit 1,000 before I knew it.  It’s just fun to shoot. After the initial spray of Rogue American Apparel’s gun lube into the action and barrel, I never lubed or performed any service on the gun at all until after the review was complete. And then it was just to clean up for pictures.

Of course, I couldn’t help but throw a silencer on the gun. (The .45ACP seems like it was made to suppress, since it starts out subsonic in the first place.) The birdcage flash hider unscrews and any standard .578-28 threaded can screws right on.

There were no reliability issues running suppressed, as I did for about half the rounds fired for the review.  Interestingly enough, even after running six magazines straight through the gun, the suppressor was still cool enough to hold without discomfort.

To test for accuracy I used a set of Magpul flip-up iron sights.  Shooting off a front bag, I scored consistent sub 2″ five-round groups at 50 yards. This ratio holds true out to 100 yards —  suggesting it was my eyes, not the gun, that printed 4″ 100 yard groups.

Using the ridiculously inexpensive Primary Arms Advanced Micro Dot (review pending) I averaged three inch 100 yard five-round groups for 20 rounds, using Winchester white box 230gr FMJs. My own LSWC hunting rounds and the Winchester PDX1 round shot the same three-inch group. I have no doubt that a magnified optic would produce even better results.

Please, by all that is holy, don’t put a magnified optic on this gun.

That extra almost three inches of barrel over the GLOCK 21 buys you an increase in feet-per-second of bullet travel, and the corresponding increase in muzzle energy of about 60ft-lbs, sometimes more depending on the load. If you want to run a carbine length barrel at 16″, you are looking a much greater increase in energy, as much as 200ft-lbs with many commercial loads. For the reloader willing to experiment with different powders, the longer barrels offer a great deal of potential.

Few people deny that that the .45ACP is a suitable round for self defense. And no intelligent ones do. But with the right bullet, the .45ACP can also be used as an adequate hunting round for thin skinned game, as long as the shots stay close.

I’ve taken a few deer and more than a few pigs with a 1911 Government pistol, no farther than 35 yards away. With this QC10 set up, I can ethically take the hill country whitetail deer out to 50 yards. Obviously, shot placement is key. For any kind of pistol hunting, I prefer to use a heavy hard-cast lead flat nosed or semi wadcutter round.  I don’t care about expansion at all on a .451 caliber bullet, just penetration.

At The Range at Austin, this was a fun gun to shoot. Practicing Mozambique drills or just plain old mag dumps is a blast. The recoil is so light I can pull the trigger as fast as I can at the 15-yard line, with no discipline at all, and watch as each round punches through the 4″ blue center dot of their standard targets. It’s too easy.

But the real fun is off the square range and back at home, running the steel gauntlet. This gun makes moving and shooting  a breeze. The gun moves fast, shoots fast, and carries like it’s nothing. Target transitions feel like cheating. It’s easy to forget that you’re actually throwing 230gr pills out at 900+ fps when all you hear is the dingdingdingdingding of lead on steel.

The QC10 GLF AR pistol is a .45 caliber bullet hose. Really, I can’t get enough of this thing. Suppressed? It makes me feel like a total ninja. Anybody have any recommendations for extended magazines? Because I bought the gun. ‘Nuff said?

Specifification: QC10 GLF Pistol

Frame type: GLOCK Large Frame (other magazine types available)
Caliber: .45ACP (engineered for GLOCK magazines) (other calibers available)
Upper Receiver: QC10 PMUR Milled billet 7075-T6 Aluminum
Lower Receiver: QC10 GLF Milled billet 7075-T6 Aluminum
Trigger: Mil-Spec (5lbs)
Finish: Type III Hard Coat Anodizing
Barrel: 7.5″ 4150 CMV steel, Melonite QPQ 1-in-16″ twist, medium profile (other lengths available)
Thread pitch: .578-28
Bolt: QCT 8620 steel .45ACP Melonite QPQ
Brace: QCT Custom SB Tactical Brace
Weight: 5lbs 14oz (7.5″)
Length: 24.5″ (7.5″)
MSRP: $1,645.95

Style and Finish * * * * 1/2
Well finished and without tool marks or blemishes anywhere on the gun, inside or out. Half a star removed for not perfectly matching anodizing.

Customization * * * *
Just as customizable as any AR. One star removed for lack of ambidextrous controls, which I don’t like on an AR in the first place.

Accuracy * * * * *
The limiting factor to the accuracy of this gun was the optic or my eyes. 3″ groups with a 2MOA red dot at 100 yards is great. That level of accuracy really opens up what you can do with a pistol round. As it is, it makes light game hunting with the .45ACP easy peesy at the 50-yard mark.

Reliability * * * * *
I was going to zero it out until I found it was a magazine issue for the first few magazines. After that, it ran like a spotted-ass ape.

  1. Overall * * * * 1/2
    The QC10 GLF .45ACP’s almost-but-not-quite matching finish, the handguard’s line and receiver not matching up aesthetically, the mil-spec trigger and pistol grip deny the gun the ultimate accolade that is my extremely rare 5 stars. But just barely. It’s compact, accurate, durable, reliable and fun. So much fun.


  1. avatar ATFAgentBob says:

    I’d want one if it wasn’t 1,600 dollars… I can run an MCC conversion on a Glock 21 frame (80% lowers rock!) For waaaay less or could just buy a PCC upper to put on an 80% lower….

  2. avatar ozzallos says:

    Why are these things still over a grand?

    1. avatar jwtaylor says:

      So I looked at the price for a while and compared it to other guns, and then cut all that from the article.

      Basically it costs that much because it’s a well made AR that very few people make and customers are willing to pay for it. These guys have a waiting list for their guns in many configurations, unlike just about everyone else in the AR world right now.

      The closest I could come to in quality was the more expensive Sig MPX, which uses proprietary magazines and you can have it in any caliber you want as long as it’s 9mm.

      If you want to be able to swap back and forth with the same magazines on your side arm and your sub-gun, there are relatively few options. And very few that are built from the ground up on that model. Even fewer are well made, which was one of the issues that turned me off on the whole concept from the start. I always loved the MP5 and UMP45, but I’ve been “meh” on everything else. Until this one.

      1. avatar ATFAgentBob says:

        I think they may have handicapped themselves though. Using that AR form factor many gun customers will do exactly what most of us are doing. Asking wtf they’re smokin asking that much for a pistol caliber AR pistol. Unfortunately though everybody else has screwed up all the other SMG platforms and I don’t think an M1 or mini14 platform would sell as well. The m1 in particular won’t do well because of those shitty Chiappa copies out there.

      2. avatar ozzallos says:

        But they’re all well made rifles. That’s the justification every single last one of them use. I’m sure it’s well made. Well made enough to push it over a grand when a AR prices are historically lowest prices ever ($325!!)? I understand niche. I understand well made. But srsly. I think there’s more padding in the ‘niche’ than the ‘well made’.

    2. avatar Stereodude says:

      I don’t want to be that guy, but PSA makes AR’s in .45ACP. No idea how good they are, but they’re much less than $1600.

      1. avatar Jessi says:

        Angstadt Arms Also makes a very well made Ar made exactly for pistols (receivers bolts etc) for about $600 less.

        1. avatar jwtaylor says:

          Not according to their website. If we take a look at their 9mm pistol and then add an SB Tactical brace we get up to the same price as the ones offered from qc10. I am not familiar with their product, it might be the bee’s knees.
          But it is about the same price.
          They don’t seem to offer a 45 caliber complete build.

      2. avatar raptor jesus says:

        I built a PSA pistol-caliber carbine for $500. Ran flawlessly.

  3. avatar Bob H says:

    Kriss USA makes a magazine extension for Glock 21 mags thats supposed to be 100% reliable in carbines and raises capacity to 25 rounds. It was designed for the Vector but purportedly works in any 45 caliber platform that takes Glock 21 mags.

    1. avatar jwtaylor says:

      I’ve used them and found they work just fine. Thanks for the reminder.

      1. avatar Anner says:

        Kriss mags work well, but SGM Tactical mags are far cheaper. No issues with them in a variety of pistols and carbines.

  4. avatar GS650G says:

    Yeah 16 large is a lot of money. That’s really tricked out AR territory.

    1. avatar jwtaylor says:

      “Large” means $1,000.

      1. avatar OmnivorousBeorn says:

        Like he said, $16,000 is a seriously tricked out AR. =P

        1. avatar Joe R. says:


          Beyond “Operator” territory. We’re talking Bilzerian territory just below gold plated AK warlord territory.

  5. avatar ATFAgentBob says:

    Considering the TNW is round 700 and will still take GLOCK mags… I can’t justify that much money on a rifle platform pistol.

  6. avatar little horn says:

    i don’t get it

    1. avatar JasonM says:

      Then clearly you haven’t shot a PCC.
      I thought they were a bit gimmicky when the Scorpion came out, but I bought a Scorpion, because it was the new CZ that nobody could get.
      Now I have a Scorpion SBR, tricked out with HB replacement parts, a Mystic X can, and a CZ Custom trigger job, an MPX SBR (that one’s a bit meh), and last month I built a tricked out 9mm AR rifle.

  7. avatar ACP_arms says:

    Jon, Do you think you could get your hands on a CMMG Guard in .45ACP to try out?

    1. avatar jwtaylor says:

      Happy to ask.

  8. avatar Soylent Green says:

    I love the PCC. I have a JP GMR in 9mm and it’s fantastic. I’m planning a super shorty 9mm pistol for suppressed range fun build but sometimes I wonder if a super shorty in 45ACP would be better. I don’t have anything in 45 currently, and already load 9mm, so it makes it hard to switch

  9. avatar RogUinta says:

    I built a QC10 9mm SBR for under a grand…INCLUDING the stamp. I’m not sure how you can get to $1600 for one, even if it’s in .45 ACP.

    That said, I like my QC10 9mm lower. A lot. My only regret is that the mag catch is not ambi-friendly at all.

  10. avatar MDH says:

    Pretty sweet! I like it for the same reasons I like an MP5. That’s a lot of stopping power in a compact package.

  11. avatar M1Lou says:

    I was meh on PCCs until I built a 9mm AR and bought a CZ Scorpion. They are a lot of fun and fairly economical to shoot. I didn’t look at .45 ACP models as .45 isn’t as economical. If I am going to that price point, I might as well go with 5.56. QC10 looks like they make a multitude of neat products, but I haven’t had the chance to check anything out by them.

    My favorite local range only allows pistols or PCCs in the steel bays, so it was well worth it to own these two guns to shoot with. You can do a decent job of training with both of them, and they are a heck of a lot of fun. I do need a can for my Scorpion. The 9mm AR is a 16″ barrel so it is really quiet. That is usually the first thing people mention when they shoot it.

  12. avatar JasonM says:

    Anybody have any recommendations for extended magazines?
    Taylor Freelance and MBX make them for 9mm and .40. I don’t think many people use a .45ACP PCC in competition, because USPSA and IDPA both score it as minor power factor, so there’s not much of a market for it. Just get a 9mm for plinking. Think of all the money you’ll save in ammo…by spending an extra $1500.

    I have the QC10 lower on my 9mm AR PCC (I went with a New Frontier upper, because T-handles are Terrible), and I found the mag release button to be very sticky with my 36 & 47-round magazines’ super springs. The Odin Works extended mag release is a nice addition.

    …this accepts standard AR replacement [trigger]s
    That might not be entirely true. Yes, they’ll fit, but many triggers designed for 5.56mm ARs don’t work well with the pistol calibers (at least 9mm). The Elftmann, for example, will frequently fail to catch the hammer, causing it to follow the bolt back forward (usually without enough energy to activate the primer, but sometimes it will be a machine gun). The Hipertouch 24C, seems to be the best trigger available for PCCs.

  13. avatar Jeff O. says:


    Just last night I was looking at what it would cost to build a .45 ACP AR upper as I thought it would be super fun.

    Turns out it’s hard to find parts.

  14. avatar Specialist38 says:

    You state the brace is a crappy stock.

    Your review of the shooting would indicate that it makes a pretty good stock.

    What say you?

    1. avatar jwtaylor says:

      I say read this part again:

      After shooting it, I changed my mind.

      Chambered in 45ACP, the QC10 Nighthawk doesn’t generate enough recoil to matter. The brace stays in place no matter where you put it: arm, chest, shoulder or belly button (really, I have no idea what kids do these days). Top it with a red dot optic — as almost everyone using the Nighthawk will — and your cheek-stock-weld isn’t nearly as important as it would be if your were looking through a magnified optic or iron sights.

      1. avatar Specialist38 says:

        I did not see ” i changed my mind” when originally reading the article.

        I think you you edited it. Lol

  15. avatar Cloudbuster says:

    What makes this worth ~$1000 more than a Berretta or Kel-Tec PCC?

    1. avatar Pete Zaitcev says:

      There’s no Kel-Tec PCC in .45 ACP.

      1. avatar Cloudbuster says:

        So, you are saying .45 ACP instead of 9mm or .40 is worth $1000? Really? You could buy a Kel-Tec Sub2k or a Beretta CX-4 storm and have enough left over to buy yourself a new handgun in 9mm or .40 … AND still have more left to buy a bunch of ammo to shoot through them!

        You know, Hi-Point has a PCC carbine in .45 ACP. You can buy, like, 5 of them for what this costs. Arm your whole militia squad! 🙂

        You can buy a sweet-looking Thompson semi-auto repro for about $1000.

        There are other AR-Pattern .45 ACP PCC’s available in the $700-ish range.

  16. avatar jwm says:

    Another Red Green fan.

    1. avatar jwtaylor says:

      Holy crap, Someone caught that. Thank you sir, you have read kindled my hope in humanity. I say “the man’s prayer” every day.

      1. avatar George Humphries says:

        I’m a newbie I guess. Educate me on the “man’s prayer”?

    2. avatar What About Bob says:

      LOLed when I read that, thank you!

  17. avatar Pete Zaitcev says:

    Here’s a simple truth about PCCs in .45 ACP: a blowback design either is massive or falls apart after 2000 rounds fired. The CMMG Guard with a brace and 8″ barrel weighs 4.7 lbs. This thing checks in at 5.9 lbs. More than a pound of bolt slamming your buffer every time you pull the trigger. I would even rather have one of those DI RMW ARs than this, not to mention the Guard. Also, bespoke parts? How is that a good thing on an AR?! If you want a vaguely AR-like PCC, buy a JRC.

    1. avatar jwtaylor says:

      I’m at about 2k rounds now with no obvious signs of wear. I could turn this gun back in and no one would know the difference.
      Your opinion does not match reality.

      1. avatar Pete says:

        The circle-10 thing is heavy, because it’s a blowback. It is not an opinion, it’s a fact.

        1. avatar jwtaylor says:

          Your opinion of what is heavy is very different than mine.

  18. avatar Warren says:

    I’d love to shoot one just for the fun factor. I don’t think I’ll ever own one. Maybe shooting one would change my mind.

  19. avatar Allan Hoch says:

    Kriss makes extentions for magazines for the vector pistols and rifles. And in 45 acp

  20. avatar Matthew Miecznikowski says:

    I picked up the CMMG in 45acp and I totally understand your love for the gun. I’ve actually moved off 556 to only shoot this not to mention it’s cheaper to plink with. I picked up the CMMG for a little over the grand and if you order it direct they will anodize it in any color you want no charge. Endless fun so glad reliable 45acp has come to an AR platform!!!

  21. I’d love to shoot one only for the fun factor. I don’t think I’ll ever claim one. Possibly shooting one would alter my opinion.

  22. avatar Docduracoat says:

    I also was doubtful on the PCC concept
    I’ve shot Tommy guns and MP 5’s and they are fun
    I was bored with AR’s and AK’s and bought a CZ Scorpion
    It is the most fun gun to shoot!
    9 mm is the cheapest ammo to shoot
    The CZ bump-fires at an incredibly rapid rate
    I now see why PCC’s are so popular

  23. avatar C F Ring says:

    Love my quality ARs. However, enjoy and shoot just as much (maybe more) my HiPoint 9mm, 45 cal. carbines. Now eagerly waiting for 10mm. Great fun, accurate, indoor ranges Winter. Oh forgot, $300 !!!!!!!!
    I’ll now await the elite gun snobs’ abuse.

    1. avatar jwtaylor says:

      Fun guns are the best guns.

  24. Pistol caliber carbines are stupid.

  25. avatar Mikial says:

    “I ended up doing a lot more malfunction drills than transition drills; the G21 had the exact same problem. I didn’t have a firearm issue, I had a magazine issue.”

    You have to be a member of one of the smallest minorities in the world if you are having significnet malfunctions with a G21, or any Glock that involved magazine issues unless you weren’t using Glock magazines. Having said that, I have had significant issues with a JRC rifle in .45 that used Glock magazines, but it sure wasn’t the magazines since they worked flawlessly in my G21’s.

    1. avatar jwtaylor says:

      It was a large enough minority to find multiple threads about the same issue on different forums.
      Glocks fail. It’s not a weird thing. It’s not a big deal.

Write a Comment

Your email address will not be published. Required fields are marked *

button to share on facebook
button to tweet
button to share via email