One of these is the starting point to design your customized 1911 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.

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




  • 9mm
  • 10mm
  • 45 ACP
  • 460 Roland


To the left: a 1911 frame ready to install into a CCU Upper. No modifications to the frame are needed! Complete lowers only are readily available from many sources. This allows a user to have a dedicated lower for their CCU. Particularly for 1911’s there are many sources for all internal components and naked frames allowing the more adventurous to build a dedicated lower for their CCU’s the way they want it. None of the 1911 upper components are needed.

1911 NOTES:

Frame Size Compatibility: The only concern regarding what will fit and what will not fit is the length of the frame’s dust cover. There are a few frames which have dust covers longer than a standard Government model and these may not fit the CCU. Commander and Officer models will work so long as the dust cover is not more than 1/2″ shorter than it is on the Government model. Double stack magazine models work fine as long as the rails/trigger/hammer are all standard 1911 spec. Double Action “1911s” do NOT work with the CCU.

You should purchase the CCU to match the caliber that your pistol was designed for.

Last Round Hold-Open – there is no last round hold-open function on the CCU.

Thumb Safety Lever – only the original GI style safety will function with the 1911 CCU. Extended and ambidextrous safeties will not function as a safety but the CCU will function and fire in all other respects.

Grip Safety – this still works when the CCU is used.


Certain 1911 style pistols such as the Paraordnance line have modified receivers which leave an opening in the magazine well in an area critical to proper feeding when these pistols are used with a CCU. Mech Tech has designed an insert called a ‘Para Block’ which solves the problem. Frames with ‘ramped barrels’ can be used with the CCU by installing the ‘Parablock’. The photos below illustrate the difference between a ‘standard’ barrel (left photo) and a ‘ramped barrel’ (right photo).

NOTE: Factory Loaded Ammunition Only. MechTech recommends only using good quality factory loaded ammunition in the CCU. 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: ‘COLT’ is a registered trade name and is in no way affiliated with Mech Tech Systems Inc. There are many other manufacturers of 1911 style pistols and the fact that Mech Tech Systems Inc. provides the CCU system as an accessory item for these pistols is in no way intended to imply that any of these manufacturers endorse or are associated with Mech Tech Systems Inc.