Mag Position Tester! (Edit)
Mark Serbu demonstrates a 3D-printed fixture designed to test various magazine catch positions for blowback-operated pistols. The fixture allows for precise adjustments in both vertical and horizontal planes, enabling the user to find the optimal position for reliable feeding. By incorporating weight into the simulated bolt, the fixture helps analyze the momentum required for successful chambering, with high-speed video used to observe the feeding dynamics.











