One of these is the starting point to design your customized Glock Carbine Conversion Unit (CCU). Each base model (shown below) comes with a 6″ Standard Rail and Molded Fore Grip. If you have your own M4 stock, buffer tube, castle nut and lock ring, our M4 Adapter will accept both commercial and Mil-Spec tubes. Every unit is test fired before it ships. Other rail choices are available which may replace the Standard Rail/Molded Fore Grip. All of our rails are Picatinny. Choose from our ACCESSORIES page to customize your CCU.


* All Gen. 5 Models WILL NOT WORK on our CCU’s

To ask questions, or if you are ready to place an order, please call us at 866-433-2122




The CCU’s fit Glock frames that are Compact (G19, G23, G32), Standard (G17, G22, G24, G31, G34, G35) and Large (G20, G40, G21, G41). Mech Tech Uppers are not available for sub-compact Glocks. Generation doesn’t matter, but the front rail size does – see the picture and note below. Compensated and SF versions only affect the barrel/slide and grip size respectively, they will work just fine with the CCU. If you have a G31 or G32 you can only order the CCU in 9mm or 40S&W.

Glock magazines are interchangeable within the same frame size, and between the Compact and Standard sizes. This means, for example, that if you have a Glock 22 and want to shoot 9mm with your CCU, you can. Just purchase Glock 17 magazines. Compact magazines are too short to work in Standard frames. Here are the combinations that will work:

Your frame:      CCU Available in:

Compact                9mm, 40S&W

Standard                9mm, 40S&W

Large                      45ACP, 10mm

Again, make sure your magazine caliber matches the barrel caliber of your CCU.

This information is provided only to illustrate the flexibility of the Mech Tech CCU. (Caution: the foregoing does not imply that a Glock pistol designed for a given cartridge can safely shoot a different cartridge by simply switching the magazine – this is dangerous – do not try it! Likewise a CCU Upper can safely fire only the cartridge for which it is designed!) If further clarification is needed please contact MechTech Systems Inc.

Glock front rail top down largeIf your early model Glock frame has a front tab length longer than the red line dimension then it will not fit our CCU. The tabs, metal and possibly plastic (as shown in the picture) are what engage the slot in the pistol’s slide. If your frame doesn’t have any plastic tab, just the metal tab, your frame will work.

Glock-lock-block-pins-v2-compressorIf your early model Glock has only 1 pin instead of the 2 pins shown, the CCU feed ramp will not fit on the locking block in your pistol. Therefore, your pistol will not work with the CCU.

Aftermarket triggers. Sometimes aftermarket triggers, while they work fine with the pistol slide and barrel, don’t work with the CCU. The problem is not consistent enough to say that XYZ Trigger will not work with the CCU. Due to tolerance stacking your aftermarket trigger MAY not work with the CCU. The CCU is designed to work with factory triggers.

CCU vs Pistol Slide: There is no last round hold open with the CCU. With the CCU attached your pistol and drop safeties still work.

Cominolli Safety: The CCU and this manual safety do work together, however, they do interfere with each other a little bit. The Telestock will only fully collapse if the safety is off. In the on position the safety lever blocks the rod of the Telestock from moving forward.

The “Feed Ramp”

The Feed Ramp is placed in the Glock lower. This item is necessary for proper feeding. There are 2 sizes – specify Glock model when ordering. One Feed Ramp comes with each CCU. The block is not actually attached to the lower – just sits there during assembly of the CCU upper. When the upper is in place the ramp is trapped. A small magnet keeps the ramp in place during assembly/disassembly.

NOTE: Factory Loaded Ammunition Only. Mech Tech recommends only using good quality factory loaded ammunition in the CCU which meets SAAMI, CIP or NATO standards. The CCU is a blowback operated action and is capable of safely firing ammunition up to +P. DO NOT USE +P+ or ‘hotter’ loads.

NOTE: “Glock” is a registered trade name and Mech Tech Systems Inc. is not affiliated with Glock. Glock has not endorsed the CCU and the fact that Mech Tech Systems Inc. provides the CCU as a Glock accessory in no way is intended to imply that Glock sanctions or is in any way associated with the product.