The Lahti L-39 is a Finnish semi-automatic anti-tank rifle, designed in 1939 by firearms designer Aimo Lahti and used by Finnish forces in the Winter War (1939–1940) and Continuation War (1941–1944) against the USSR.  It fires the Swiss 20×138mmB cartridge, which was originally developed for the Solothurn S-18/1000 rifle.
lahti l-39