AR-15/M-16 - BCG Disassembly & Assembly

This video from School of the American Rifle highlights critical manufacturing defects in AR-15 bolt carrier keys, specifically focusing on rough internal bores. Lead instructor demonstrates how a poorly finished carrier key can cause significant friction, premature wear on components like gas tubes, and operational issues, contrasting a problematic new Colt carrier with a well-functioning older model. The expert emphasizes the importance of a smooth bore for reliable function and longevity of expensive parts.

This guide, presented by School of the American Rifle, details how to identify and replace a malformed weld spring in an AR-15 Delta Ring assembly. A misaligned weld spring can cause the gas tube to be pushed off-center, leading to excessive friction or damage to the carrier key and gas tube. Replacing the faulty component ensures proper gas tube alignment and firearm reliability.

This guide details the process of diagnosing and fixing a significant rail wobble issue on a new Daniel Defense Mk18 upper receiver. The primary cause identified was a hand-tight barrel nut, compromising the stability of the RIS II rail system. The steps involve disassembly, inspection of the barrel nut, proper tightening with an armorer's wrench and torque wrench, and reassembly. This addresses a critical quality control failure that can affect firearm accuracy and reliability.

This guide details the evolution of AR-15 carrier key staking from early 'Gen 1' square staking to modern 'Gen 5' OCKS with serrated heads. It emphasizes proper torque values (vintage 35-40 in-lbs, modern 55-58 in-lbs) and the importance of sufficient metal displacement for screw security. The video, presented by an expert from School of the American Rifle, critiques commercial staking and references historical technical manuals.

This video provides an "autopsy" of an Anderson Manufacturing Bolt Carrier Group (BCG) that failed after only 150 rounds, specifically noting a "sheared lug." The content focuses on a detailed examination of a firearm component failure, suggesting a deep dive into the mechanical aspects and potential causes of the malfunction. This is highly relevant for firearm owners and those interested in the reliability and build quality of AR-15 platforms and their components.

This YouTube video offers practical tips and techniques for polishing stainless steel firearm components. The content focuses on achieving a high-quality finish on gun parts, likely aimed at gunsmiths, hobbyists, and firearm enthusiasts looking to customize or maintain their weapons. The video emphasizes real-world application and likely demonstrates various methods and tools used in the polishing process for stainless steel firearms.

This video provides a detailed guide on loading a 75-round drum magazine for the AK-47, specifically a Romanian variant. It covers identifying components like the follower and spring tension release, resetting the follower, and the correct procedure for inserting rounds. The tutorial also emphasizes the importance of winding the spring correctly and releasing tension for long-term storage to preserve spring health.

This beginner's guide to the AR-15 covers essential external components, controls, and the basic cycle of operation. It emphasizes proper magazine seating with a firm 'whack' and demonstrates field stripping for cleaning. The video highlights key aftermarket parts from brands like Magpul and Battle Arms Development, offering practical advice for new AR-15 owners.

This video demonstrates the proper installation of an A2 style flash hider on an AR-15 barrel, emphasizing critical steps for optimal performance. Key takeaways include using a crush washer with the correct orientation, applying grease to threads, and precisely indexing the device to prevent dust kick-up when shooting prone. The speaker highlights the importance of aligning the solid portion downwards and using a pin to verify alignment with the gas port for a secure and functional installation.

This video details the critical process of checking headspace on an AR-15 build, emphasizing safety and proper function. It covers the complete disassembly of the bolt carrier group, the precise use of 'Go' and 'No-Go' gauges to verify chamber dimensions, and the reassembly of the BCG. The demonstration highlights the importance of ensuring the bolt does not close on a 'No-Go' gauge to prevent dangerous headspace issues.