On March 12, 1999 Poland joined the North Atlantic Treaty Organisation. A problem arose with modifying the weapons of the Polish Army to use the standard NATO ammunition. A decision was made to develop a new general-purpose machine gun. The construction was based on the design of the successful PKM machine gun that was previously produced under licence in Poland. To use the common NATO ammunition, the feeding method of the machine gun had to be fundamentally modified. The metallic disintegrating link specifically designed for ammunition belt-fedfirearms and rimless 7.62×51mm NATO rounds used by NATO is a push-through design. The UKM machine gun extracts 7.62×51mm NATO rounds from open-M13 links by pushing them forward out of the link directly into the chamber for firing. The non-disintegrating closed-link metallic belt type used in the PKM machine gun is a pull-out design, which extracts the rimmed 7.62×54mmR rounds by pulling them rearward out of the link. In the second stage the rimmed rounds are pushed forward into the chamber for firing. The 7.62×54mmR machine gun feed pawl mechanism is radically different than that of 7.62×51mm NATO chambered machine guns based on the MG 42 machine gun feeding method, using a small, simple pivoting arm pushed out to the right side by the bolt carrier, rather than a much larger articulated feed cam, lever, and pawl assembly. The UKM-2000 is a primary general-purpose machine gun on most vehicles used by Polish Forces in Afghanistan and is a coaxial machine gun in KTO Rosomak and Polish-modernized BRDM-2. There is a proposal of modernization of the Polish UKM-2000 GPMG fed by 7.62×51mm NATO to the new UKM-2013 standard. The upgraded GPMG will be equipped with a new folding and telescopic buttstock with a cheekpiece and additional grip/pod, the integrated Picatinny rail with iron sight and 3-rail forehand attached to the gas tube, new grip, new cocking handle new safety switch selector, a new 440-mm barrel plus some additional internal changes. The Polish Army is interested in this machine gun fed from the 100-round soft ammo bag instead of a steel box. Because of external similarity to the Russian PKM GPMG chambered to the 7.62×54mmR some elements like a buttstock, a grip or a forehand with rails will able to be used with the Kalashnikov design.
Variants
UKM-2000C - coaxial version of UKM-2000, successor of the PKT. Use on KTO Rosomak and some Polish modernized BRDM-2. Modifications include the removal of the stock, a longer and heavier barrel, a gas regulator and an electric solenoid trigger.
UKM-2000P - standard GPMG version, some also equipped with MIL-STD-1913 rail.
UKM-2000Z - first attempt to modernization of UKM-2000, new telescoping stock and black polymer pistol grip. It wasn't adopted.
UKM-2013C - modernization of UKM-2000C presented in 2012
UKM-2013P - modernization of UKM-2000P presented in 2012, better ergonomy and functionality, new folding and telescopic buttstock with a cheekpiece and additional grip/pod, the integrated Picatinny rail with iron sight and 3-rail forehand attached to the gas tube, new grip, new cocking handle new safety switch selector, a new 440-mm barrel plus some additional internal changes, new soft ammo bag instead of typical for PK family steel box magazine
UKM-2000M/UKM-2015 - version that will be in tests in mid-2014, probably to introduction in 2015
The L in a coaxial version denotes the ammunition is fed from the left instead of from the right. There is also a company in the United States that builds semiautomatic UKM rifles for civilian use.
