The MechTech Systems Carbine Conversion Unit (CCU) is by far the world’s most versatile pistol accessory. The CCU is essentially an upper for your semi-automatic pistol, so if you own a Glock, a 1911 or a Springfield XD, you can convert it into a pistol-caliber carbine. Essentially functioning as an AR-style upper receiver once mounted in place, the non-serialized MechTech CCU replaces the host gun’s slide and barrel assembly, allowing the carbine to retain the pistol’s superb single-action trigger and comfortable grip angle.

The MechTech CCU isn’t legally considered a firearm, so it can be shipped right to your doorstep. It also installs on your pistol’s frame with no tools, and it takes only seconds to make the transition from handgun to carbine.

This all sounded way too good when I called MechTech to order a CCU for my Sig Sauer 1911. Well, let me tell you, it is not too good to be true. In fact, it really is the ultimate pistol accessory. The CCU transformed my pistol into a totally different gun — a beast at the range that now rides in my truck because of its versatility. The gun is small, easy to operate and can be converted back to a pistol in just seconds. And because the CCU-equipped 1911 uses readily available .45 ACP ammo, it’s great for self-defense or taking out a coyote without taking up too much space in my ride. And if you needed any more convincing, the MechTech CCU also increases the performance, accuracy and ballistics of the host gun in virtually every way.

Locked & Loaded

Installing the CCU is quick and easy. Remove the host gun’s barrel assembly and slide. Then just align the rails inside the CCU with those on the frame, and slide the frame forward as far as it will go. Reinstalling the 1911’s slide stop secures the components together and voila, you went from pistol to carbine in seconds. And changing it back to a pistol is just as easy: Just pull the slide stop pin out, pull back on the frame to release it from the CCU and reassemble your pistol.

MechTech makes the CCU out of rolled steel with a powder-coated finish and a corrosion-resistant interior coating. The rolled steel does make the CCU a bit on the heavy side, however, that weight does help reduce recoil quite a bit. The CCU’s cylindrical housing encases a simple blowback operating system that uses the energy exerted by expanding gases from firing to cycle the action. An extractor located on the bolt draws the spent case from the chamber, where it is expelled from the upper by the pistol’s ejector. The bolt’s rearward motion is then stopped upon contact with a thick rubber block, and the gun’s recoil springs drive the action closed again, stripping a fresh cartridge from the detachable box magazine and chambering it along the way. One noteworthy consideration is that the CCU does not lock back on an empty magazine.

The charging handle is found on the left side of the unit; there’s no longer a slide to rack. Shooters can lock the bolt in the open position by retracting the handle and then pushing in on it until it engages a small round notch in the wall of the housing. Even after conversion to a rifle, the CCU utilizes the host 1911’s grip, thumb safeties and magazine release.

I have a set of Crimson Trace Lasergrips on my 1911 and was hoping the laser would still work after conversion. However, the laser just hits my support hand when I’m holding the forend. There is no comfortable way to hold the rifle and utilize the Lasergrips, unfortunately, but you could add a laser or a light onto the rail if you wanted to.

MechTech also offers a wide variety of options and accessories for your CCU. You can customize the “upper” with four different stock options, different rail configurations, lights, lasers, sights and vertical foregrips. I ordered my unit with an adjustable M4-style stock, a mini rail kit and a flash suppressor. I also wanted to stick with the Sig Sauer theme. So I went to Sig for a brand-new ROMEO5 red-dot sight to mount on top of the new weapon.

The MechTech CCU is Grin Inducing

The best part of this system is that installing the CCU requires no permanent modifications to your host pistol. I love shooting my 1911, so being able to go from pistol to carbine in seconds is a great feature.

On the range, the MechTech CCU is a real joy to shoot. It’s everything you’d want from a pistol-caliber carbine. Although I did find it to be a little on the heavy side, it was extremely accurate once I dialed in the Sig ROMEO5. The CCU managed to produce groups in the 2-inch range at 100 yards on average; I can manage the same with the Sig Sauer 1911 on its own at 25 yards.

I put about 500 rounds through the CCU with only one malfunction, which occurred during the very first round I put through it. It just failed to fire. There was no primer strike or anything. So I don’t know if the round just didn’t seat properly or if I’d done something wrong. I did remove and reinstall the CCU probably 20 times before I went to the range; it may have had something to do with that. After that initial malfunction, the CCU worked flawlessly with every kind of ammunition I fed it.

This is a very easy-to-shoot setup that earns a lot of smiles and attention at the range. Once other shooters found out what it was, they had to try it out. I always welcome other shooters to try out my firearms, especially when I’m at the range specifically for testing. So it was great to see that the CCU would function well with any shooter working the trigger.

So, this accessory adapts to your existing pistol frame in seconds, utilizes existing magazines and ammunition, and has multiple uses. It is extremely fun to shoot at the range. Also, you can also hunt small game with it, use it for home defense or just tuck it away in your truck or trunk of your car. I choose this application for the gun because of its versatility and accuracy. I also like the fact that I can always switch back to my standard 1911 setup.

MechTech’s CCU represents a paperwork-free accessory that boosts ballistics in a platform that you are already familiar with. It will also make your pistol more versatile and easier to shoot. Given the level of accuracy and reliability that I encountered during testing, it is very easy to see why someone who already possesses a compatible handgun would find such a product appealing. If you own a Glock, a 1911 or anything in the Springfield XD family, then you can order your very own MechTech CCU and transform your standard pistol into a mid-range carbine.

For more information about the MechTech CCU, please visit

This article was originally published in Gun Buyer’s Annual 2019. To order a copy, please visit

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