The HK 33 is a derivative of the G3 rifle firing the 5.56x45mm round. It was developed in the 1960's by German arms manufacturer Heckler & Koch. The HK 33 was a successful design but did not sell as much as the G3. Since 2001 the HK 33 is no longer in production, except for license production in Turkey. The HK 33 remains in service with many of its users, especially law enforcement units like it for its accuracy and reliability.