PSA Upper Receiver Autopsy - Part 1

This video demonstrates how to identify a 'clocked' barrel extension in an AR-15 upper receiver, a common issue arising from over-torqued barrel nuts. The instructor highlights visual cues like misaligned feed ramps and explains potential causes, including bent index pins or manufacturing defects. The guide also suggests a practical test using a handguard to confirm the misalignment.

This video details the inspection of a PSA/H&R XM177 complete upper receiver, identifying two critical issues: a clocked barrel extension preventing proper seating of components and a significantly misaligned front sight base. The instructor demonstrates how to diagnose these problems using alignment gauges and component fitment, noting that headspace passes but the issues require correction. Potential solutions like oversized taper pins and proper jig use are discussed, emphasizing the importance of thorough inspection before building.

This guide outlines how to build an RPK-inspired rifle on an AR-15 platform. Key modifications include a 24-inch barrel for accuracy, a large muzzle brake for rapid follow-up shots, a bipod for stability, and a fixed stock for consistency. A side-charging upper is also suggested for easier reloading.

This video details a highly unusual Enfield revolver modification featuring a significantly extended 25-inch barrel. The expert explains the process of chopping the original barrel and threading in a custom-made smoothbore barrel, noting the machining and finishing details. The discussion also touches on UK firearms law regarding barrel length and bore type, and the proofing marks indicating the modification was officially inspected.

This guide details the process of pinning and welding a muzzle device to an AR-15 barrel. This modification is crucial for meeting the 16-inch minimum barrel length requirement under NFA regulations, thereby avoiding SBR classification. The video highlights both the benefits, such as NFA compliance and improved balance, and the drawbacks, including reduced serviceability of components behind the muzzle device and the permanent nature of the attachment. Instruction is provided by a professional with high authority, likely a gunsmith or experienced firearm instructor.

This video details the MK3 Firearms' new MK IV SD offering, a modified Ruger Mark IV pistol designed to convert standard 22LR supersonic ammunition to subsonic. The modification involves extending the barrel and adding ports to stabilize the round, improving accuracy at distance. It also features Vorten internals for an enhanced trigger and a custom metallic four-color woodland camouflage Cerakote finish.

This guide details the process of diagnosing and repairing an owner-induced feeding problem in an AR-15 upper receiver, specifically addressing a burr on the barrel extension's feed ramp. Expert gunsmith Chad Albrecht demonstrates meticulous inspection, burr removal, and polishing techniques to restore reliable feeding. The video emphasizes that such modifications, while often overlooked, are valid solutions for specific AR-15 malfunctions.

This guide details a diagnostic technique for AR-15 bolt carrier groups, focusing on efficiency rather than simple pass/fail. Developed by Chad Albrecht of School of the American Rifle, it uses custom gauges and cutaway components to illustrate gas dynamics, critical seals, and potential failure points like gas leaks. This advanced method helps troubleshoot functionality issues and understand the nuances of the AR-15's internal gas system.

This video provides a critical, expert-level inspection of a problematic AR-15 Bolt Carrier Group (BCG) by Chad Albrecht of School of the American Rifle. The analysis details numerous manufacturing defects, including an undersized bolt tail, excessive firing pin protrusion, oversized firing pin and cam pin holes, and a failing headspace check. The content highlights the importance of precision gauging in identifying critical failure points that impact rifle reliability and safety.

This guide details a specialized technique for swapping an AR-15 rear takedown pin without requiring a full disassembly. It leverages insights from Chad Albrecht of School of the American Rifle, emphasizing the use of a modified 1/16 inch Allen wrench or a specialized tool to manage the detent. This method is particularly useful for AR-15 variants with collapsible stocks, offering a more efficient approach to maintenance.