Avia Bk-534, Czechoslovak Users

Now it's the time for the last post about the Avia B-534, this time covering the native and some foreign and exotic users of the Bk-534.

The Bk-534 was designed to have a 20mm Oerlikon FFS-20 cannon firing through the nose and just two 7.92mm machine guns firing through the sides of the nose.
Apparently there were some problems to adapt the new gun that weren't solved until the summer of 1938. In order to make more airplanes, Avia decided to replace the cannon with a third machine gun in the nose with an extra amount of ammunition.
As the time was running out due to the German occupation of the Sudetenland, two series of the Bk-534 were produced, with only three of the second batch serving in the Czechoslovak Air Force and the remaining 63 ones serving either with the Luftwaffe or the Slovak Air Force after March 1939 when the rest of the Czechoslovak state was occupied by Germany.

Sources:
1. https://en.wikipedia.org/wiki/Avia_B-534
2. Salamander Books - The Complete Book of FIghters