Firing port


A firing port, sometimes called a pistol port, is a small opening in armored vehicles, fortified structures, or other armored equipment that allows small arms to be safely fired out of the vehicle at enemy infantry, often to cover vehicle or building blindspots. Examples of this can be seen in the Crusader tank, Sherman tank, Tiger I, T-34-85, and even modern armored vehicles today such as the Mechanized Infantry Combat Vehicle program, its successor the Bradley Fighting Vehicle featuring the M231 Firing Port Weapon, and Russian armored personnel carriers. Some firing ports are improvised for such use. For example a late production Tiger I manual shows the Nahverteidigungswaffe being used as a firing port.
Some pistol ports, such as on the Sherman, included vision slits such as "protectoscopes" increasing visibility around the tank.

Ballistic weakspot

Being a ballistic weak spot, firing ports are often reinforced with additional armor, and in subsequent designs reduced in number, or deleted. Other armor is improvised such as slat armor to stop shaped charges or chicken wire to stop grenades.
However due to strong tanker demand they are sometimes brought back as happened with the Sherman. This was in part due to its use during ammo resupply in the Sherman, eliminating the need for an additional crew member to pass ammo through the loader hatch, instead being able to simply pass the ammo from the ground through the firing port.
One of the Tiger I firing ports was converted into a loader escape hatch and the other covered with an armor plug and eventually deleted from the design to improve production time and reduce costs.