Notes from HJL:

April 28th is the birthday of Aimo Johannes Lahti (born in 1896.) This clever Finn designed (or co-designed) an amazing array of weapons including the L-35 Lahti pistol, Suomi M-31 SMG, the Lahti-Saloranta M/26 LMG, the the famous Lahti L-39 20mm anti-tank rifle, and even the 20 ItK 40(a 20 mm dual anti-aircraft cannon).