Good & Bad Gas/Carrier Keys - Mil-spec is not Mil-spec

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 YouTube video focuses on a common and crucial aspect of firearm ownership: the buffer system. The title, "What buffer system do you use?", directly asks for viewer input on their preferred buffer systems. While the description is empty, the title alone indicates a discussion or inquiry into different buffer systems, which are vital components for the reliable operation of firearms, particularly semi-automatic rifles like the AR-15 platform. Viewers interested in firearm maintenance, customization, or performance optimization would find this content relevant.

This video focuses on AR-15 lower parts kits, guiding viewers on how to select the right one for their build. It highlights the importance of understanding the differences between kits to ensure a successful firearm assembly. The description also encourages viewers to sign up for CMMG Insider updates and provides links to CMMG's website and social media channels for more information on releases and company news.

This YouTube video, titled 'Bore Buddy – Não é FRT Totalmente Automático', appears to focus on a firearm accessory or modification called 'Bore Buddy'. The title explicitly states it is *not* a fully automatic FRT (Forced Reset Trigger), suggesting the content will clarify the functionality and potentially limitations or comparisons of this device. Given the focus on a specific firearm component and the clarification regarding its automatic capability, the video likely aims to inform viewers about its use, installation, or performance, potentially differentiating it from fully automatic triggers.

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 details the diagnosis and repair of a feeding issue on a Sons of Liberty Gun Works East India upper receiver. The root cause was identified as a sharp burr on the barrel extension's feed ramp, causing rounds to jam. The solution involved polishing the feed ramps and adding a secondary bevel, replicating Colt's design, which successfully resolved the malfunction.

This video demonstrates the internal mechanics of an AR-15 bolt carrier group using cutaway models. It highlights the importance of internal bore dimensions for gas system efficiency and explains how to diagnose potential issues like gas leaks. The demonstration covers the cycle of operation, critical seals, and common manufacturing defects, offering advanced insights for AR-15 maintenance and troubleshooting.

This video provides a detailed autopsy of a faulty AR-15 Bolt Carrier Group (BCG). The analysis reveals critical manufacturing defects including an undersized bolt tail failing gauges, excessive firing pin protrusion causing pierced primers, an oversized firing pin hole, and an oversized cam pin hole leading to headspace issues. These flaws significantly compromise the BCG's function and reliability.

This video demonstrates a specialized technique for swapping an AR-15 rear takedown pin without full firearm disassembly. It highlights the use of a custom-fabricated tool, often made from a 1/16 inch Allen wrench, to depress the detent. The method allows for efficient pin replacement, particularly useful on rifles with staked castle nuts, by leveraging the old pin to guide the new one into place.