K-7

The K7 originated from a Republic of Korea Army Special Warfare Command requirement for an integrally suppressed submachine gun cheaper to procure than the Heckler & Koch MP5SD6 already in Korean service. Although the MP5SD6 had been fielded, its cost — and that of domestically produced submachine guns — led most special forces units to rely on unconventional weapons for covert operations. Development began in April 1998 under the Defense Agency for Technology and Quality, part of the Agency for Defense Development, together with Daewoo Telecom, a subsidiary of the Daewoo Group. The project concluded in December 2000. The weapon was first shown abroad at the IDEX 2003 exhibition in the United Arab Emirates. Production is now handled by SNT Motiv, the successor to Daewoo Telecom.

The K7 derives from the Daewoo K1A assault rifle but replaces its direct gas impingement system with simple blowback operation. The bolt reciprocates during firing and locks back when the magazine is exhausted. The upper receiver is a modified K2 component, while the hammer and fire control unit and the telescopic stock come from the K1; many parts remain interchangeable between the two weapons. The magazine well of the K1A was retained, with internal adaptations for the shorter 9 mm magazine; besides the standard vertical box magazine, the weapon accepts IMI Uzi and Beretta Model 12 magazines. The fire selector offers semi-automatic, three-round burst and fully automatic settings, though sustained automatic fire has been found to damage the baffles of the integral suppressor. The light bolt produces a high cyclic rate. The integral suppressor allows the use of standard 9×19 mm Parabellum ammunition rather than subsonic loads, and distorts the report sufficiently to complicate location of the firer. Noise measurements taken three metres from the muzzle in semi-automatic fire recorded 93.5 dB with the suppressor fitted against 117 dB without it. Stated suppressor service life is 2,000 rounds, although manufacturer testing reported no performance loss after 6,000 rounds, and no degradation was recorded in examples used by the South Korean military over seventeen years. A PK Designlab weaponlight with integral Picatinny rail can be mounted.

In South Korean service the K7 is used by the Army Special Warfare Command and the Navy Special Warfare Flotilla. Indonesia is the largest operator, issuing the weapon to the Kopaska tactical diver group and to Kopassus; a 2019 SIPRI small arms report recorded about 1,786 K7s transferred to Indonesia, and by 2021 the Indonesian inventory was six times the size of the South Korean one. Bangladesh employs the type with SWADS, and the Royal Papua New Guinea Constabulary also operates it. Two examples were transferred to Thailand for trials according to the same 2019 SIPRI report. Iran unveiled a domestically produced submachine gun based on the K7 in 2020, displayed in suppressed and unsuppressed forms at the Victory Day National Arms Exhibition on 24 May 2021; on 20 March 2023 a bodyguard of President Ebrahim Raisi was photographed carrying a K7. In March 2024 the Korea Customs Service reported that a former SNT employee had illegally exported roughly 480,000 copied gun parts and items of production equipment, valued at ₩26.6 billion, to a state-owned defence contractor in the Middle East between September 2019 and March 2023.