ADEX 2025 – SNT Motiv unveils the K4-II, South Korea’s next-generation automatic grenade launcher
South Korea unveiled its new K4-II automatic grenade launcher at the Seoul ADEX 2025 exhibition, marking a major step in the country’s ongoing effort to modernise its ground forces. Developed by SNT Motiv, the K4-II is an advanced evolution of the long-serving K4, embodying the growing integration of digital technologies and the nation’s ambition to reinforce its leadership in infantry support weapons
Originally designed in the 1990s by Daewoo Precision Industries as a 40×53 mm automatic grenade launcher comparable to the American Mk19, the K4 has been a mainstay of South Korean forces for decades. The new K4-II, however, is a thoroughly upgraded version: lighter, more compact, and more efficient, tailored to modern urban and asymmetric combat scenarios.
Technically, the K4-II retains the same 40×53 mm NATO-calibre ammunition but introduces significant improvements. Its redesigned alloy body reduces overall mass; the original K4’s weapon had a mass of 34.4 kg, the K4-II mass being 26.5 kg, a 7.9 kg saving. No data were provided about the mass of the tripod, which is certainly reduced compared to the legacy one; that of the K4 tripod is 29.5 kg, which means a total mass of around 65 kg, the K4-II being certainly lighter. The new internal feed mechanism enhances reliability and supports a slightly higher rate of fire, around 340 rounds per minute. Its effective range remains approximately 1,500 metres but with improved accuracy thanks to a modern optoelectronic sighting system compatible with thermal and infrared optics.
Ergonomically, the updates are equally notable: a redesigned carrying handle, and a quick-deployable adjustable tripod. The weapon is also fully compatible with light armoured vehicles and remote-controlled weapon stations. A full-length Picatinny rail now adorns the upper receiver, allowing integration of aiming devices, laser rangefinders, and ballistic computers. All of this reduces set-up time while enhancing battlefield versatility.
Compared to its predecessor, the K4-II provides smoother recoil absorption and easier maintenance, greatly boosting field reliability. It is compatible with the new dual-effect K212 high-explosive grenades as well as the KM385 training rounds, broadening its tactical and instructional use.
Its debut at ADEX 2025 highlights South Korea’s growing defence export ambitions under the “K-Defense” banner. SNT Motiv aims to position the K4-II as a world-class contender in the automatic grenade launcher market, rivalling established Western manufacturers such as FN Herstal and General Dynamics. Compact, modern, and powerful, the K4-II symbolises a new milestone in the evolution of South Korea’s fire-support capabilities.
Photo J. Roukoz
