PSA M16 Phosphate/Chrome BCG - Abbreviated Autopsy

This guide details the inspection of an AR-15 bolt carrier group (BCG) after extensive use, focusing on identifying wear and potential failure points. It covers checking the bolt, gas rings, extractor, firing pin, and bolt carrier for stress fractures, damage, and carbon buildup. The video emphasizes that parts wear out over time and regular inspection is crucial for maintaining reliability, especially after high round counts exceeding 30,000 rounds.

This video addresses common issues found in two KAK bolt carrier groups (BCGs), specifically focusing on damaged extractor pivot pins. The instructor demonstrates how rolled-over pins prevent proper extractor function and require replacement. Additionally, rough surface finishes in the carrier key tunnel bore are highlighted as potential causes of premature wear and cycling issues.

This video demonstrates a critical inspection for LMT bolt carrier groups, specifically checking the torque on the carrier key screws. Using a Wheeler FAT Wrench, the instructor performs a breakaway test at 20 and 30 inch-pounds to identify broken or under-torqued screws. The video highlights the importance of this check to prevent potential failures and outlines options for resolution, including contacting the manufacturer or performing a replacement and proper staking.

This video announces the release of the School of the American Rifle's AR-15 Bolt Carrier Group (BCG) and Gas System Gauge Set. These gauges are designed to measure critical dimensions of the BCG, including the carrier body, bolt tail, and gas key, to assess efficiency and proper function. The set also includes pin gauges for carrier key alignment and a gas path gauge to check for obstructions. While some specialized gauges are not yet available due to manufacturing challenges, the released set aims to provide users with a deeper understanding of their AR-15's internal workings and potential gas system inefficiencies.

This video provides a detailed, expert-level inspection of a Sons of Liberty Gunworks Bolt Carrier Group (BCG). The instructor, a certified Sons of Liberty armoror, walks through numerous tests including gas ring functionality, bolt component integrity, dimensional checks with gauges, magnetic particle inspection, and a critical magazine binding test. The analysis emphasizes the importance of these checks for reliability and longevity, highlighting specific features like the five-coil extractor spring and chrome silicone ejector spring.

This video provides an in-depth physical inspection of a Knight's Armament SR-15 Mod 2 rifle, highlighting its unique design features and proprietary components. The instructor demonstrates specialized tools and techniques required for working on KAC firearms, emphasizing differences from standard AR-15 platforms. Key areas covered include the bolt and barrel extension design, gas system, ambidextrous lower receiver, bolt carrier group specifics, and various dimensional checks for headspace, throat erosion, and alignment.

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.