Thanks to unforseen circumstances upon which I shall enlarge when it's not 1AM, I will be without a DF-capable computer for the next few months...
Or not, as it turns out. 43 FPS on embark is good enough to be getting on with, so I'll try and nail some of the bugs with the workshops. I'm also going to experiment with ceramic ammunition, at least for spring-guns.
After that is the next big development: Rockets. This is where I depart somewhat from actual history, though the use of rockets as artillery is older than you might think. Absent support for throwing weapons in fortress mode, I'm aiming for something that resembles a Renaissance-era gunsmith's attempt at an M79. I've got these mostly worked out in my head, but I'd be interested in some recommendations from you folks before I kick off.
For experimenting with ceramic ammo, you might want to consider creating a new type of material, paired with a new reaction that creates the material.
The edge damage setup used for gunstones and cartridges relies on the cutting properties of the bullet material. I have no idea what the properties are for porcelain or clay goods, but I doubt Toady created them with ceramic ammunition in mind.
Perhaps tie the reaction to the alchemy skill.
I think maybe gunpowder creation should be changed to alchemy as well.
How do you plan on creating the grenade effect for the m79?
I have no idea on how you would start, but having a dragonfire or magma mist effect would be interesting.