Soviet 37 mm artillery gun designed to be mounted on armored vehicles. Officially entered service in 1931. It was equipped with a semi-automatic horizontal sliding wedge. Two-turreted T-26 model 1932 and BT-2 tanks carried such guns.

How to Get B-3 37mm
Tools + Hotchkiss

B-3 37mm Doodle Tanks Combo
+Rolled = MS-1 Turret
+Elliptical Turret = T-26
+Elliptical Turret = Blocked