4 KAK NP3 Dual Ejector Bolt Abbreviated Autopsies Part 2/2 - Bad Ejector Pins

This guide details how to tune an AR-15 platform firearm when using a dual ejector bolt. Dual ejector bolts can require adjustments to the buffer weight and spring to ensure proper cycling and bolt lock-back. The expert instruction emphasizes starting with lighter components if issues arise and testing thoroughly.

This guide details the disassembly and reassembly of an Arisaka Type 30 bolt, focusing on replacing a cracked safety/sear component. The process involves careful compression of the firing pin assembly to separate the split bolt halves and precise reassembly. The video also covers reloading for the .257 Roberts cartridge and troubleshooting sight issues on a sporterized Arisaka.

This guide details the process of replacing the firing pin spring in a Remington 700 rifle. It outlines the use of a cord and dime trick for initial spring compression, followed by a specialized jig for full decompression and pin removal. The steps cover disassembly, spring replacement, and reassembly, emphasizing careful alignment and tension management. The video suggests this maintenance may address accuracy issues, though the demonstration showed minimal impact.

This video details extensive gunsmithing required to repair and improve a Kennedy rifle, highlighting common failure points and John Browning's design principles. The instructor demonstrates how to remake critical screws, repair worn carrier components, and modify the cartridge lifter mechanism to ensure reliable function. The work involves welding, drilling, tapping, and careful fitting to overcome wear and design limitations, ultimately aiming to achieve the reliability of designs like the Winchester 1886.

This video provides an expert-level examination of a battle-worn Berthier 1907-15 rifle, detailing its WWI history through various markings and modifications. Ian McCollum, a recognized firearms expert, explains the rifle's development, colonial use, and its role as a substitute standard infantry arm. The analysis covers production details, arsenal markings, German capture stamps, and evidence of depot-level repairs, offering deep insights into French military logistics and firearm evolution during the Great War.

This guide provides a detailed, step-by-step procedure for fixing a common tight bolt issue on Mosin Nagant rifles, specifically demonstrated on a Finn M39 variant. Expert instruction from Eric of Moss Pawn & Gun details how to identify and rectify the problem by carefully filing and peening the bolt face edges, resulting in a significantly smoother bolt operation. The video emphasizes practical gunsmithing techniques for maintaining military surplus firearms.

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.