The “pistol port” on a sherman was primarily for ejecting spent ammo cases, not shooting a pistol thru. A number of other tanks, including the German Leopard series, have used them. The ultimate form of this is the shell ejection system used in Russian tanks, T-72, etc.
Some early-mid Tiger 1s had pistol ports as seen here:
I know David Byrden has tons of information on Tigers.
Ken