The K1 assault rifle was developed in 1977-1982 by the South Korean company Daewoo Precision Industries Ltd (a division of the large industrial corporation DAEWOO International Corp.) as a replacement for the license-built M16A1 rifles, used by the South Korean Army during the 1970s. The improved version, Daewoo K2, appeared circa 1984 and replaced the K1 rifle in production and service. At the present time the K2 assault rifle and K1A1 carbine are the general issue shoulder arms with the South Korean Army. Semi-automatic only, export versions of the K2 rifle, known as a Daewoo DR-100 (pre-1994), DR-200 (post-1994, both chambered for .223 Remington cartridge) and DR-300(post-1994, chambered for Russian7.62x39mm cartridge), are intended for the civilian and police markets. The earlier K1 semi-automatic versions were exported from Korea as Daewoo MAX-1 and MAX-2 rifles (both in .223 caliber).
The K1 rifles were designed as improved variations of the M16 rifle. While retaining most of the M16 design features, Daewoo designers replaced the direct gas system of the AR-15/M16 rifle with the more common and reliable gas piston system, and made several other improvements, resulting in very good combat weapon.
The Daewoo K1 is a gas operated, selective fire, magazine fed weapon. The K1 rifle and K1A1carbine differs from the K2 rifle by different gas system, shorter barrel with different muzzle compensator / flash hider (K1A1 carbine only), and different type of buttstock.
The K1 rifle had the gas system similar to the one found in AR-15/M16 rifles, with no separate gas piston and gases being directed straight into the bolt carrier. The return spring with its guide rod is located behind and partially inside the gas piston rod, and, unlike the M16, does not take space in the buttstock, allowing for folding or completely retractable butt to be used.
The receiver is generally similar in design to the M16 rifle, and is made from two halves, upper and lower, machined from the aluminum alloy forgings, and linked by two cross-pins. It must be noted, however, that Daewoo receivers are NOT interchangeable with any AR-15/M16 type receivers.
The trigger unit is fitted with the 4 position safety / fire selector switch, located at the left side of the receiver, above the pistol grip. The switch has positions for Safe, Single shots, 3 rounds bursts and Full auto fire. It must be noted that the 3 rounds burst counter does not reset itself if trigger is released before all 3 rounds are fired.
The feeding is achieved by using M16-type magazines. The K1 rifle incorporate a bolt stop device, which holds the bolt open after the last shot from the magazine is fired.
The sighting system consists of the hooded front sight, mounted on the gas block, and the L-shaped dual aperture rear sight, with one small aperture for daylight conditions and another larger aperture for low light conditions. The range adjustments are made by the rotating knob at the right side of the rear sight block. Maximum range setting is 600 meters.
K1A carbine has the retractable steel wire buttstock.