LMT Enhanced Carrier - Loose Carrier Key

This expert guide from the School of the American Rifle details how to identify and address rough carrier key bores in AR-15 bolt carrier groups. The instructor, demonstrating expert knowledge, explains how these manufacturing defects, particularly on Colt components, can lead to premature wear on the gas tube and reduced reliability. Solutions involve replacing the defective carrier key to ensure smooth operation and longevity of the firearm.

This video provides an in-depth inspection of a Centurion Arms Sand Cutter V2 bolt carrier group. It details the process of identifying and replacing a firing pin due to excessive protrusion and a carrier key with an oversized bore. The instructor emphasizes the importance of proper dimensions for gas system efficiency and reliable firearm function, even noting that the staking on the original carrier key was exceptionally robust.

This guide details how to inspect an AR-15 Bolt Carrier Group (BCG) for critical defects, specifically peening marks on the carrier rails. Instruction from School of the American Rifle highlights how improper peening can lead to significant damage to the upper receiver. Proper inspection is crucial for ensuring BCG longevity and firearm safety.

This video highlights a critical issue of carrier key corrosion found on a Brownells Retro Bolt Carrier Group. The instructor demonstrates how to inspect the inside of the carrier key using a borescope, revealing significant rust on one component compared to others. This inspection is crucial to prevent accelerated wear on the gas tube.

This video provides an in-depth look at common wear points on a Rock River Arms Bolt Carrier Group (BCG). It highlights issues with gas rings, specifically a wide gap indicating potential failure, and a damaged cam pin due to excessive friction. The instructor recommends replacing these parts to ensure continued serviceability of the BCG.

This video provides an abbreviated autopsy of a KAK K-SPEC chrome bolt carrier group (BCG) exhibiting unusual corrosion after only 500 rounds. The instructor highlights issues with the extractor spring and significant roughness on the cam pin's bearing surfaces, recommending replacement for both. The analysis emphasizes the importance of smooth cam pin surfaces for preventing excessive wear on the aluminum upper receiver.

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.