Being a track-based AC in Armored Core has several advantages, one of them being the ability to mount and fire some of the game’s biggest back-mounted cannons while you’re on the ground, and in the air.
In fact, some weapons only really kick you in the balls when they’re mounted on treads. And no other weapon best exemplifies this than the chain gun, at least during their heyday in Armored Core 3. Feared for their combination of shot velocity, stopping power, and rate of fire, the chain gun was like a machine gun on steroids.