This is going to sound like weird pitch. But my idea for a Steampunk Salad Shooter round is simple: An improvised round consisting of a salad bowl filled with greasy nuts and bolts that does added range and damage, at the cost of converting to an engines only damage type.
Its mostly a "We need to slow you down buddy" type round that uses a flimsy salad bowl as an improvised sabot. Said salad bowl, however, breaks when launching, reducing the refire rate (-35%), and providing a low level of damage to the gun (-125). It also takes more space (-50% clip size) and loads slow (-25%). The benefits, however, are enormous, at 100% damage, but only to engines, with 75% projectile speed). It would also have an expanded area of effect, at +75%, but again, only damages engines.
Its primary usage, as I see it, would be to snare enemy ships, especially during crazy king. The rationale would be that said round would fling enough small metal bits into the engines that it would infiltrate the housing and seize the engines, denting and bending the fast moving propellers. These bits, however, wouldn't have enough force to do more than dent the armor or guns, and would likely bounce off the heavy canvas of the balloon. Also, it would make the most god awfully loud and annoying noise ever when fired and when hitting, comparable to "A tornado of hay-pence attacking a tin-shack"
The particulars of the benefits and costs of this round could be further tweaked, and my provided numbers might've been a bit extreme, but I certainly hope we can all agree that in addition to being a quite practical addition to the game's arsenal, it would be incredibly steampunk and cool!