The Mac & Cheese v2 is a popular, highly customizable 3D-printed firearms frame designed to accept a standard MAC-11 (or MAC-10) type upper receiver. It is widely recognized in the DIY gun-making community as an innovative way to modernize the classic, blocky MAC-11 platform.
The Mac & Cheese project blends components from multiple firearm platforms to fix the poor ergonomics of the original MAC-11.
Upper Receiver: It utilizes standard MAC-11 9mm top-charging or side-charging upper assemblies (such as those from MasterPiece Arms (MPA) or Velocity Firearms).
Lower Parts: It is designed to use AR-15 lower parts kits (LPK), including standard AR-15 triggers, safety selectors, and pistol grips. This massive ergonomic upgrade replaces the stiff, heavy trigger of the original military design.
Magazine Compatibility: It feeds from highly reliable, widely available Glock-style 9mm magazines rather than proprietary or expensive metal MAC-11 magazines.
Aesthetics: The “v2” revision specifically offers cleaner lines, optimized print settings for durability, integrated Picatinny rails for mounting braces or stocks, and a more streamlined magazine release mechanism.
Originally released by 3D-printing developers as an open-source file to be printed at home in PLA+ plastic, the design has become so iconic that it has entered commercial production. Companies like Free State Gun Co. have adapted the architecture into machined aluminum variants, known commercially as the SAS 9, allowing users who don’t own a 3D printer to buy a completed or stripped aluminum lower built on the exact same concept
