A decentralized, 9mm submachine gun file kit engineered for home fabrication. The design utilizes a 30mm x 2mm square box section for the upper receiver and standard 3D-printed PLA for the lower grip module and frame. It features a heavy blowback, open-bolt operation and is cross-compatible with standard and printable 9mm Glock-pattern magazines. The documentation includes specifications for fabricating the bolt body out of hardware-store mild square tubing and 16mm bar stock.
Complete your home defense or hobby build with this hardware specification guide for the Hybrid Square Tube SMG. This package outlines the required non-printable components, including the 25mm x 2mm mild square tube and 20mm inner tubing needed to construct the heavy blowback bolt assembly. Optimized for smooth cycling, reliability, and exact fitment with printed lower assemblies.
