Ah yes, the oft-overlooked Heatsink Clip.
...
No, this isn't gonna be a cool guide.
This thing is a bit like a Gunner's Chemspray. Both extinguish 3 stacks on use and make the component immune to future stacks-- but not to fire damage itself. The difference between Heatsink and Chemspray is that Chemspray lasts for 25 seconds and Heatsink lasts until the gun is reloaded.
Heatsink Clip reduces damage and projectile speed (and, thus, arming distance), but increases clip size.
Doesn't sound like much, does it?
Well, a nice thing is that it give guns with 2 shots (Mercury Light Field Gun, Typhon Heavy Flak, Hellhound Heavy Twin Carronade, and Beacon Light Flaregun) a third shot.
A THIRD SHOT.
You load up Heatsink into the Carronade on a Blenderfish, you start brawling with an enemy Blenderfish. (For those who don't know, a Blenderfish is a Goldfish with a Heavy Carronade on the front.) You and the enemy Gunner both start trying to shoot out each other's gun and balloon. (For the purposes of this example let's assume the enemy Gunner doesn't manage to take out your gun.) After you both fire 2 shots each, the enemy Engineers (and friendly ones, for that matter) will most likely be attempting to repair the balloon. Once the enemy's balloon is rebuilt (but not repaired) you take a potshot at it and knock it down again.
You're free to sue me for excessive parentheses