Nkm wz. 38 FK

nkm wz. 38 FK
The gun in light infantry configuration
TypeAnti-air and anti-tank heavy machine gun/autocannon
Place of originPoland
Service history
In service1938–1939
Used byPoland
WarsWorld War II
Production history
DesignerWawrzyniec Lewandowski
Designed1938
ManufacturerPaństwowa Fabryka Karabinów
Unit costzl30,000 (tank version)
Produced1938–1939
No. built55
Specifications
Mass57.6 kilograms (127 lb)
Length2,015 millimetres (79.3 in)
Barrel length1,476 millimetres (58.1 in)
Width202.5 millimetres (7.97 in)
Crew3 (PL 20A mount)/ 6 (PL 20B mount)

Shell20x138mmB
Shell weight320g
Caliber20 mm
Actionblowback
Rate of fire320-350 rpm
Muzzle velocity856 metres per second (2,810 ft/s)
Effective firing range5,000 metres (5,500 yd)/7,000 metres (7,700 yd)
Feed systembox(5/10 rounds)/drum(15/100 rounds)

The nkm wz. 38 FK (Polish military acronym meaning heaviest machine gun pattern 1938) was a 20 mm heavy machine gun (autocannon by modern terminology) produced in inter-war Poland. It was used both in anti-air and anti-tank role and was also adapted for tank use and mounted on some TKS tankettes. Mass-produced since 1938, it was used extensively during the Polish Defensive War of 1939.