Which lower parts kit should we go with for this build?

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 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 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 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 video demonstrates the installation of a Kynshot Hydraulic Buffer (RB5000) into an AR-15 platform. The presenter shows the disassembly process, highlighting the removal of the standard carbine buffer and recoil spring. The Kynshot buffer is then installed, and the firearm is reassembled and function-checked, emphasizing its role in reducing felt recoil and bolt bounce.

This review focuses on the Radian Raptor SD-SL, a gas-busting charging handle designed to mitigate gas blowback, especially when using suppressed fire on AR-15 platforms. The video demonstrates its installation and highlights its ambidextrous latches and ported shaft for gas redirection. It's presented as a high-quality aftermarket upgrade for improved shooting experience.

This video compares the audible difference between a standard AR-15 buffer spring and the Armaspec Stealth Recoil Spring (SRS). It highlights the 'twang' noise of traditional springs during charging handle operation and demonstrates how the SRS provides a significantly smoother and quieter experience. The installation process is shown to be simple, replacing the two-piece buffer and spring with a single, captured unit.

This video demonstrates the difference between a standard AR-15 buffer spring and an upgraded Sprinco Chrome Silicon spring. The Sprinco spring is shown to provide a smoother and quieter cycling action after installation. The comparison highlights the visual differences and the audible/tactile improvements in firearm operation.