STV is the abbreviation for “Vietnamese Submachine Gun”; the symbol 380 indicates the length of the gun barrel (in millimeters).

The gun is designed according to the principle of gas extraction to automatically reload for the next shot. The common feature of the STV series is that they all use 7.62x39mm bullet size and can use any standard AK-47/AKM magazine...

Factory Z111 (General Department of Defense Industry) carries out the process of assembling infantry guns. Photo: SON BINH

With a length of 900mm when the stock is opened and about 600mm when the stock is folded, the STV-380 is compactly designed with a weight (without ammunition) of about 3.6kg. The highlight of the STV-380 is the ability to mount accessories such as scopes, flashlights, lasers, grenade launchers, bayonets... on the Picatinny rails (above and below the liner). This is the development trend of modern assault rifles in the world .

Currently, Vietnam is self-sufficient in manufacturing STV guns in general, STV-380 in particular and Factory Z111 is the only unit responsible for repairing and manufacturing infantry guns (rifled barrels) with a closed technological process from creating blanks to processing, general assembly and testing, and completing products. Lieutenant Colonel Nguyen Giang Chau, Deputy Head of Technical Department, Factory Z111, said: The technical staff uses specialized modern software to design; then, the drawings are transferred to the production workshops. Based on the technical drawings, the machine will create gun parts from easy-to-melt wax. These parts are covered with quartz sand and dipped in a special solution many times to form a hard ceramic shell. After heating to remove the wax, the empty ceramic mold is filled with molten steel, forming the gun parts. At the casting workshop, molten steel is poured into these ceramic molds to create the gun parts. It is the result of a combination of material technology, heat treatment and precision mechanical engineering, demonstrating a high level of mastery of modern casting processes.

Among the components of an infantry gun, the breech block is one of the components with the most stringent technical requirements. This is the part responsible for receiving the force from the bullet when fired, controlling the opening and closing cycle of the barrel, ensuring safety, stability and accuracy for the entire system. At Factory Z111, the technology for manufacturing breech blocks for the STV-380 is deployed on a synchronous integrated line between digital design, special materials, and precision CNC machining. Each detail of the breech block from the main body to the bearing edges, slide grooves, or guide holes is machined in a strictly controlled environment for vibration, temperature and geometric accuracy. Durability, load-bearing capacity, assembly compatibility and does not affect the basic features of the weapon. For the STV-380, the breech block is one of the improved details to optimize operations, increase safety and improve the efficiency of weapon use.

The gun barrel is the "heart" of the gun, the most difficult part in design and manufacturing. It is not just a simple steel tube but the crystallization of high technology in mechanical processing, metallurgy and quality control. With STV-380, the gun barrel is manufactured with strict requirements on internal geometry, spiral grooves, barrel surface - factors that determine the accuracy, shooting stability and life of the weapon. Lieutenant Colonel Nguyen Cong Tuyen, Deputy Manager of the Barrel Workshop, Factory Z111, said: Manufacturing gun barrels must go through many stages. We apply the cold forging method - the most advanced method with 100% automation in the production of infantry gun barrels today. In addition to details and detail clusters such as gun barrels, rails, breech blocks... some steel parts of the gun such as magazines, springs, breech covers will be processed at the Factory using cold mechanical techniques. After completion, all parts will be sent to the quality control department by automatic laser machine to eliminate defective products...

The results obtained after testing the STV-380 gun at Factory Z111 and verifying it on the training ground show the efforts of our country's defense industry in gradually shifting from importing technology to mastering technology in the direction of building a self-reliant, self-reliant, modern, and dual-purpose Vietnamese defense industry.

    Source: https://www.qdnd.vn/quoc-phong-an-ninh/xay-dung-quan-doi/sung-tieu-lien-stv-380-buoc-tien-cua-cong-nghiep-quoc-phong-viet-nam-1012135