Actually, the AR15 is not DI - Direct Impingement? Sort of.

This guide explains the function of the buffer tube in an AR-15 or AR-pattern rifle, as demonstrated by Jared from GUNBROS. The buffer tube is a critical component of the operating system, housing a buffer and spring. Upon firing, the bolt carrier group compresses this spring and buffer assembly as it moves rearward, and the subsequent expansion of the spring drives the BCG forward to chamber the next round. This process is essential for the semi-automatic function of AR-pattern firearms.

The Iraqveteran8888 "Meltdown" video series, while primarily for entertainment, offers educational insights into firearm durability under extreme stress. The videos demonstrate that AR-15 gas tubes are a common failure point, often exploding around 650-750 rounds of full-auto fire. This testing highlights the importance of materials like Inconel for components subjected to high heat and pressure, suggesting potential for improved firearm design and longevity.

This guide details the essential steps for lubricating a new AR-style rifle before its initial firing, as demonstrated by an experienced instructor. It covers proper disassembly, specific lubrication points on the bolt carrier group and trigger mechanism, and reassembly. The video emphasizes the importance of lubrication for new firearms, drawing a parallel to car maintenance, and highlights the performance of the We The Pieu MX1 lubricant in hot conditions like those found in Utah.

This video from Brownells, featuring Caleb, explores the optimal zero distances for an AR-15, primarily for competition use. It analyzes four common zero distances: 25, 36, 50, and 100 yards, detailing their impact zones on an IPSC A-zone target at various ranges. The instructor emphasizes that the 'best' zero is dependent on the intended use of the firearm and the optic employed, recommending the 100-yard zero as a versatile option for experienced shooters, while suggesting 36 or 50 yards for those using red dots or LPVOs respectively, especially for closer engagements.

This video demonstrates the proper procedure for loading and unloading both primary (rifle) and secondary (pistol) weapon systems, emphasizing a specific order for safety and efficiency. It covers magazine insertion, slide/bolt manipulation, and chamber verification, along with tactical considerations for managing ammunition and readiness.

John Lovell, demonstrating expert-level knowledge of the AR-15 platform, explains the function of the forward assist. This feature is designed to manually drive the bolt carrier group fully into battery when fouling, debris, or other issues prevent it from seating properly. Lovell compares its utility to backup sights, emphasizing its value as a redundancy for ensuring reliable operation, especially in adverse conditions.

This short explains the meaning of the 'П' marking on Kalashnikov rifles, which signifies the 'Postoyannaya' or battle sight zero. The zero distance varies by caliber: 300 meters for 7.62x39mm (like the AK-103) and 400 meters for 5.45x39mm variants (AK-74, AK-105, AK-12). The AKS-74U 'Krink' has a 200-meter battle sight zero.

This guide details the field stripping and cleaning process for the Ruger Mark IV Tactical .22LR, emphasizing its improved single-button takedown. Expert analysis highlights its reliability and suitability as a suppressor host, with a timed cleaning demonstration showing efficiency.

This guide details the technique for engaging targets at extreme ranges with a Kar98k Sniper and ZF39 scope, as demonstrated by 9-Hole Reviews. It emphasizes using the reticle for ranging and holdovers due to the lack of external adjustment dials, requiring significant shooter skill in estimating wind and elevation. The instruction highlights the historical context of German sniper doctrine and the practical application of vintage optics for long-range accuracy.

This review details a practical accuracy test of the M21 SWS, a sniper variant of the M14 rifle, chambered in .308 Winchester. The test engaged targets from 150 to 800 yards under challenging environmental conditions. Despite a mechanical jam and shooter error, the rifle achieved a 32 out of 40 hit ratio, demonstrating its capability at extended ranges.