Hydra Flak Tank
The Hydra Flak Tank is a specialised weapons system used by the Imperial Guard and designed to take out enemy air support.
Overview
The Hydra is based on the Chimera chassis, replacing its troop carrying abilities with a big gun turret on top, munitions and targeting systems for its weapon, and the fuel to haul it all around. Its weapon is normally associated with fixed platforms, but the Hydra is made for the purpose of deploying anti-air support in non-permanent locations and as a mobile backup.
The Hydra's primary weapon are four long-barreled Hydra Autocannons, weapons that are basically just Autocannons with extended barrels. This does give them better range and penetration, though, as it gives more time (barrel length) for the projectile to accelerate (begins decelerating after leaving the barrel). They are mounted on the side of the turret, allowing a cone of fire that encompasses pretty much anything located above the Hydra. Though the individual weapons are not very strong (they require a 6 to penetrate armor 12), the sheer amount of bullets they pump out (4 twin-linked shots per turn) means that they will take the enemy down with sheer rate of fire. Thanks to their superior targeting systems, enemy vehicles and Jetbikes won't get cover saves from going flat out or turbo-boosting, so they will eat Jetbikes for breakfast. Though not being the most dakka in the Imperial Guard, the Hydra certainly is up there in the bullets-to-firepower ratio.
If needed, the Hydra can commit its weapons to anti-infantry purposes, ripping through anything wearing carapace armor with ease and forcing even MEQs to rethink their chances. At half the cost of a Leman Russ Exterminator and being able to field up to 3 in the same Heavy Support slot, you may want to rethink how much dakka you want for your points. Unfortunately, the almighty Hydra has now been rendered unable to hit ground units with its amazing autocannons (even with twin linked) with any sort of accuracy, making it close to usele-*BLAM* being the best anti-aircraft vehicle in the -*BLAM* the best ground-based anti-aircra-*BLAM*, for the mighty Tau are much scarier to flyers!! SHUDDUP WE HAZ LOOTAZ
Now, for those of us with curiosity and a brain *BLAM*... there is some fluff with the Hydra being a triple-A gun platform. That is Anti-Air-Artillery, the stuff in world war two that made the black clouds of shrapnel. So, if the Hydra can use explosive ammunition, why can't the infantry auto-cannons use the same? Possibly because Flak Rounds are unwieldy in use for infantry Heavy Weapon Teams due to increased recoil and great danger of danger close accidents. And in all honesty, it appears that Hydra's fluff schizophrenically jumps between Bullet Hell and Black clouds of Shrapnel Doom™.