Thunderbolt (1974)

Seven years after a daring bank robbery involving an anti-tank gun used to blow open a vault, the robbery team temporarily puts aside their mutual suspicions to repeat the crime after they are unable to find the loot from the original heist, hidden behind a school chalkboard. The hardened artilleryman and his flippant, irresponsible young sidekick are the two wild cards in the deck of jokers.