Flak gun
From FreeSpace Wiki
General
Flak guns were designed nearly the same time beam weapons were. They rather focus on combat against fighters than warships. Even though, flak guns are also effective against other smaller-sized ships such as transports, freighters or even weaker cruisers. When a projectile of flak explodes, it has a short damage radius, which makes it ideal against fighters and especially bombers.
Flak projectiles usually do more damage on hull plating than on shields. Flak guns are also known to be nearly useless against subsystems.
