When the Polish Army modernized to NATO standards and adopted the Kbs wz. 96 / FB "Beryl" assault rifle of 5.56x45mm NATO chambering in 1997, thought was given to developing a true, belt-fed, gas-operated Light Machine Gun (LMG) form to operate alongside it. The work resulted in the Kbkm wz. 2003 which attempted to succeed the long-running, Soviet-era PKM machine guns in 7.62x54mm chambering then in widespread Polish Army service.
The weapon featured the tried-and-true gas-operated, rotating bolt action common to many automatic weapons today. Feeding was by way of a 200-round disintegrating-link belt (held in a hard pouch) but the system could equally feed from 20- and 30-round Kbs wz. 96 detachable magazines as well. Chambered for the ubiquitous 5.56x45mm NATO intermediate rifle cartridge, the weapon's internal workings could manage a rate-of-fire of 650 to 1,000 rounds-per-minute. Weight reached 7.5kg and overall length was 1,099mm. The barrel assembly measured 500mm long.
Its outward design was conventional and dominated by its large rectangular receiver frame. The barrel was fitted over the gas cylinder which was used to control rate-of-fire. The muzzle was slotted and iron sights fitted over the gun. A collapsible bipod could be added to the gas cylinder for support. The aft-end of the weapon was traditional with a full shoulder stock, angled pistol grip, and charging handle to manage the function of the machine gun. Belt ammunition was loaded through side ports as the original design carried a dual-feeding capability. A carrying handle over the receiver facilitated transport of the weapon.
Two versions of the gun were developed: the Kbkm wz. 2003D and the wz.2003S. The D-model was the standard, fixed shoulder stock, full-length form while the S-model was intended for airborne troops and thus given a folding skeletal stock with shortened barrel and gas cylinder - making transport that much easier for these lightly-equipped troops.
Work on the design was disrupted in November of 2000 with the end of its original developer - Zaklady Metalowe Lucznik SA. With the establishment of Fabryka Broni Lucznik-Radom SP in April of 2001, work resume and, at this time, the opportunity was taken to simplify certain aspects of the machine gun - as such the dual-feeding quality was ultimately dropped and the trigger group was revised. Work lasted into 2003 by which point the gun was being readied for state-level testing. However, Polish authorities did not suggest adoption of the gun into the Army inventory, marking the end of its development.
In the end, the weapon's design existed only in prototype form for its part in history and little else came from the project - the Polish Army instead electing to adopt the "UKM-2000" - ironically enough this was local development of the Soviet-era PK/PKS machine gun in 7.62mm chambering (specifically 7.62x51mm NATO).