Here's a terrible weapon idea.
A field artillery piece just stuffed onto a medium gun slot. Nobody knows how the gunner managed to get that thing on there, but there it is.
Arming range: 600m
Direct: 180 Explosive
Burst: 220 Explosive, 15m radius
Only one shot. 8 second reload.
With charged rounds, this does 728 damage to hull, killing everything but a Spire, Goldfish, and Galleon in one direct hit. But you have to get a direct hit. At 600m. With Lochnagar, it does 1260 damage to hull and has a more reasonable 360m arming range. Only a Galleon is surviving that.
Within its arming range, you're only getting a one-hit-kill if shooting at a Squid or Junker with Loch. Still hurts though.
Turning Speed: Think Lochnagar Artemis.
Turning Arcs: Think H Flak.
For high-risk high-reward sniper junkies. Probably horribly underpowered due to arming range. Probably hilarious to kill someone with it.
Discussion, reasons why this is an awful idea, reasons why I'm an awful person, and accusations that I don't play the game below.