Daewoo K2 The Daewoo K2 , appeared circa 1987 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 Russian 7 . 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 K2 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 . Technical description . . The Daewoo K2 is a gas operated , selective fire , magazine fed weapon . The K1 rifle and K1A1 carbine 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 K2 gas system features a long stroke gas piston , located above the barrel . The bolt group is more or less similar in design to the M16 design , with rotating bolt that have 7 lugs and locks directly into the barrel extension . The cocking handle is attached to the right side of the bolt carrier and reciprocates when gun is fired . Some sources , however , stated that 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 . Both K2 and K1 rifles 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 . K2 also can be fitted with the see - thru scope rail just ahead of the rear sight block . The K2 rifle is fitted with the side - folding plastic buttstock and plastic furniture . K1A1 carbine has the retractable steel wire buttstock