HK33 had been developed by the German company Heckler und Koch in mid- to late 1960s as a scaled-down version of their G3 battle rifle, and entered production in 1968. HK33 was developed for then-new cartridge, 5.56x45mm (.223 Remington), and while it had not been adopted by German military, it saw significant use by some West Germany police and security units, and also widely exported, and used by Malaysia, Chile and Thailand armed forces. Since 1999, HK33 also manufactured under license in Turkey. HK33 is still in production in Germany by HK, and also served as a platform for further developments, such as G-41 assault rifle and HK53 compact assault rifle (known by the HK as submachine gun).