AR-15 - How To Check Headspace

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 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 entry details the unique XR-86 custom rifle, a 1986 build by Wilfred Ellis. It masterfully combines components from an M60 (flash hider), an M14 (gas system), and an AR-15 (trigger, bolt, locking system). The AR-15 trigger is notably rotated 90 degrees, and its bolt is integrated with the M14 gas system, showcasing advanced gunsmithing.

This guide, presented by an expert firearms instructor, details the benefits and installation of adjustable triggers for platforms like the AR-15. It covers understanding trigger mechanics, adjusting pull weight, reset, and overtravel, and highlights ideal users for these components. The instruction emphasizes safety and practical application for competition and precision shooting.

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 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 delves into the critical role of AR-15 buffers in rifle operation, explaining how buffer weight affects cycling and reliability. It details the principle of selecting the heaviest buffer that still allows bolt lock-back on an empty magazine. The content compares various buffer weights and discusses how heavier buffers can compensate for overgassing, preventing extraction issues like ripped casings or double feeds by slowing bolt carrier group velocity.