A Special MPi-81 for an Infantry Fighting Vehicle

The Steyr MPi-81 is an Austrian submachine gun heavily inspired by the Uzi design, developed in the late 1960s. It features a telescoping bolt, a grip-mounted magazine, and a cross-bolt fire selector with a progressive trigger for full-auto fire. The MPi-81 incorporates a collapsing wire stock and a non-reciprocating charging handle, along with a dual sear safety system for enhanced reliability.

The Steyr MPi-69 is an Austrian submachine gun, often compared to the Uzi, known for its rarity. During range testing, it exhibited a surprisingly slow and controllable rate of fire, with minimal vertical bounce. A unique feature is its charging handle integrated into the front sling swivel, which includes a locking tab to prevent accidental bolt retraction during hip-firing techniques.

The Steyr MPi-69, developed in the 1960s, is an Austrian submachine gun heavily influenced by the Uzi design. It features a unique charging handle integrated into the front sling swivel, proprietary 25/32-round magazines, and a three-position wire stock. While it served the Austrian Army until 1981, it is now a rare firearm, especially transferable examples in the US.

This video details the history and technical evolution of the B&T MP9/TP9, tracing its origins from a Steyr project. Key improvements by B&T include the addition of a stock and the adoption of a standard Picatinny rail. The firearm's unique rotating barrel, short recoil operation, and innovative bolt manipulation feature using a 9mm cartridge are highlighted.

The Steyr AUG (StG 77) is a revolutionary bullpup rifle featuring an integrated 1.5x optic and extensive polymer construction. Its progressive trigger allows for both semi-automatic and full-automatic fire with a single trigger pull. The rifle also boasts a quick-change barrel system and a fully polymer fire control group.

The Steyr ACR was a 1990s bullpup rifle developed for a US military program, notable for its polymer construction and unique flechette ammunition. Firing needle-like projectiles at an extreme 4,800 fps, it featured an open-bolt action and a distinctive ring primer for reliable ignition. While innovative, it represented a departure from conventional firearm design.

This video details the unique 'French Finger Trap' issue with the MAS-36 rifle's bayonet, where two rifles can become unintentionally locked together. A 1951 French arsenal memorandum identified this problem, proposing a simple modification to the bayonet handle. Drilling a small hole allows a tool, like a firing pin, to depress the internal spring, enabling the separation of locked rifles.

The M134 Minigun is a scaled-down 7.62 NATO rotary cannon, requiring 24V DC power and consuming 1.5 kW. Its high rate of fire (3,000+ RPM) is essential for aircraft engagement windows. The complex delinker mechanism is critical for feeding ammunition, and practical hand-held use is impossible due to weight and recoil. Live fire demonstrates rapid ammunition consumption and the need for indirect aiming.

The H&K G11 is a revolutionary prototype assault rifle designed in the late 20th century, notable for its caseless ammunition and unique rotating drum bolt mechanism. Despite advanced features like a 2000 RPM burst fire rate and integrated optics, its development was ultimately halted by geopolitical shifts and cost concerns.

This video demonstrates the assembly and live-fire of the German 1936 pattern light mortar (L.Gr.W.36). It highlights the mortar's leveling mechanism for accuracy and the difficulty in visually tracking its 50mm projectiles after firing. The content showcases historical military hardware and its operational use.