The K7 submachine gun was developed by Daewoo Precision Industries Ltd Co, a subsidiary to the large DAEWOO Corporation. Daewoo K7 was developed to provide less expensive alternative to German-made HK MP5SD submachine guns, used by South Korean Special Forces. To achieve minimal costs and controls compatibility with other small arms in service with South Korean armed forces, K7 utilizes as many parts from Daewoo-made K1A and K2 assault rifles as possible. Daewoo K7 submachine gun is used by Special Forces of the South Korea and Indonesia.
Daewoo K7 submachine gun is blowback-operated, selective fired submachine gun. It fires from closed bolt, and employs hammer / fire control unit of the K1A assault carbine, borrowed along with aluminum alloy lower receiver. K7 is fitted with bolt hold-open device that holds the bolt open when last round from magazine is fired. The upper receiver is a modified K2 part, with omitted gas system. Telescoping buttstock is also borrowed from K1A carbine. Large magazine well has a special plug installed to accomodate shorter 9mm magazines. The most important feature of the K7 is its integral silencer, which is "wrapped" around the barrel and is said to reduce the sound signature down to about 120 dB.