The GB-357

The Serbu GB-22 is highlighted as an exceptionally simple firearm, constructed from only four parts and chambered in .22 LR. Its minimalist design is evident in its thin profile and open-slide loading mechanism. The firearm features a threaded barrel, making it suppressor-ready, and demonstrates a unique single-shot operation.

This video features gun designer Mark Serbu discussing the GB-22 pistol. The content focuses on the design of the GB-22 and a detailed page-by-page walkthrough of its drawings, aimed at individuals planning to build one. It's an in-depth look for those interested in the technical aspects of firearm design and construction.

Mark Serbu details the complex process of converting a CNC lathe into a 12-barrel blank-firing machine gun. The project highlights the critical role of a lathe's C Axis for precise rotational control and the application of PID control theory to overcome initial firing failures. Modifications were made to ensure the device fires blanks only, avoiding legal issues.

This video demonstrates how to rifle a barrel in a home shop using basic tools, bypassing expensive CNC equipment. It covers material preparation, precise drilling and reaming, and the critical process of pushing a rifling button. While a DIY approach is shown to be possible, the video highlights the significant difference in quality and precision achievable with professional CNC machining.

This video provides an in-depth analysis of the Serbu RN-50 rifle that experienced a catastrophic failure during a Kentucky Ballistics test. Mark Serbu, the designer, meticulously examines the damage, noting severely bent steel side plates, sheared-off breech cap ears, and a sheared pivot pin. The inspection also covers the breech cap's condition, barrel threads, and the stuck casing, revealing a case head separation.

Mark Serbu, designer of the RN-50, addresses a catastrophic failure experienced by Kentucky Ballistics. He reassures customers about the RN-50's safety, attributing the incident to counterfeit or over-pressured ammunition. Serbu highlights the rarity of such events and emphasizes industry transparency, noting that his company has produced approximately 1,400 RN-50s since 2016 with hundreds of thousands of rounds fired without issue.