Ciężki karabin maszynowy wz. 25

The ckm wz. 25 Hotchkiss (military acronym for "heavy machine gun pattern 1925, Hotchkiss") was a Polish derivative of the Hotchkiss M1914 machine gun, rechambered for 7.92×57mm Mauser ammunition.

Ciężki karabin maszynowy wz. 25
A ckm wz. 25 machine gun crew during exercise, 1931
Type	Heavy machine gun
Place of origin	Poland
Service history
In service	1926 - 1939
Used by	Poland Nazi Germany
Wars	Invasion of Poland
Production history
No. built	1249
Specifications
Cartridge	7.92×57mm Mauser
Action	gas-actuated
Rate of fire	450–600 round/min
Feed system	30 round strip

Design

This Polish modification of the Hotchkiss Mle.1914 was designed in late 1924 and speedily pressed into service with the Polish Army. At least 1249 were bought in France, and subsequently used in the Polish Army since 1926.

It was not a successful design, though. Due to a higher velocity of a stronger ammunition, the barrel was warming up quickly, which caused too much barrel wear and, as a result, deterioration of accuracy. The ckm wz. 25 had a tendency to jam, and damages of some parts were more frequent, than in the earlier wz. 14, especially susceptible was the firing pin. As a result, the wz. 25 was withdrawn from infantry service and relegated to Border Defence Corps and artillery units. Some weapons were further modified in the 1930s and used as the main machine gun in Polish armoured cars. Feeding was provided by a standard 30-round metal feed strip.

Some Polish ckm wz. 25 guns were captured by the Wehrmacht during the German and Soviet invasion of Poland of 1939 and pressed into German service as 7,9 mm sMG 238(p).