The development of tank cannons has gone through phases from smoothbore to rifled, and then back to smoothbore.
Initially, most tank cannons were smoothbore, and the "Saint Chammon" being equipped with a 75mm cannon was considered an exception.
That was because tanks were more rudimentary, and most people perceived them as "bullet shields" without high accuracy requirements for the cannon.
However, as tank development progressed, the battlefield's demands for tank cannons grew higher, leading to the gradual adoption of rifled cannons.
Compared to smoothbore cannons, rifled cannons had several advantages: longer range and higher accuracy.
This often played a crucial role in tank battles:
When two tanks of equal distance and armor capabilities met, the accurate rifled cannon could often secure a decisive hit and emerge victorious.
This was a fatal blow to smoothbore cannons, so most tank cannons during the Second World War adopted rifling.
