DD Mk18 no Bueno pt2

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 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 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.

Gun magazines are surprisingly complex despite their low cost. Their design must account for the non-symmetrical geometry of rounds and varying spring pressures to ensure consistent feeding. The market paradoxically demands extreme reliability from these multi-part mechanical devices while expecting them to be very inexpensive, often under $25.

This video explains the importance of proper red dot sight zeroing for firearms. It highlights the common mistake of zeroing at 5 yards, which leads to inaccurate shots at longer distances due to the sight's height over bore. A 15-yard zero for 9mm handguns is recommended for a flatter trajectory, hitting the point of aim at 15 yards and often again at 50 yards.

The Kel-Tec P50 is a unique firearm chambered in 5.7x28mm, notable for its extremely lightweight design and surprisingly low recoil, even with a 20-round capacity. Despite a long trigger pull, its performance, with a 40-grain projectile at 1600 fps, offers comparable stopping power to .380 ACP with less felt recoil. The P50 utilizes an unusual top-loading stripper clip mechanism.

This video emphasizes aiming for the pelvis in defensive scenarios, explaining its structural importance for immobilizing a threat. It highlights this technique as effective against body armor and taller opponents. The content features a 2011-style pistol with a red dot optic and discusses tactical target selection with a humorous, direct approach.

This video clarifies the true purpose of co-witnessing red dot sights with iron sights. It emphasizes that they should operate independently, with the red dot's position within the optic window not affecting the point of impact due to parallax-free design. Co-witnessing is primarily for backup when the electronic sight fails, not for simultaneous aiming.