First development versions prior UB M52 are known under designation BB-3,
brdski bacač 3 (). The Universal Mortar UB M52 is developed from 1948 to 1951 and fires fin-stabilized
ammunition from a
smoothbore barrel. It is first mortar with capabilities to fire with wheels mounted. It has hydraulic muzzle attached to barrel to reduce pressure. M52 because of its weight require trucks or other vehicle to move them to battlefield, but compared to
field artillery it is lighter. It can be deployed on battlefield in less than a minute.
Variants M52 has 4 variants: • basic variant M52 • improved variant M52A1 - reduced weight with some smaller parts, used rubber instead of leather for parts, new hydraulic fluid • improved variant M52A2 - has one cylinder less with improved muzzle • improved variant M52A3 - new hydraulic fluid with included fluid level indicator • improved variant M52A4 - pneumatic tires. ==Deployment==