And also there's this at least: Alchemical Crossbow
For some strange reason it doesn't work with bombs better than lesser.
Also there's a flamethrower and several other items which use alchemy in the new book Treasure Vault
There is Alchemical Shot from the Gunslinger feat list. And the Alchemical Crossbow item.
Those don't do exactly what you are looking for, but they are a good foundation for a balanced homebrew.
And also there's this at least: Alchemical CrossbowFor some strange reason it doesn't work with bombs better than lesser.
Probably because Fall of Plaguestone only runs through character level 4.
Rules would need to be developed and balanced for using bombs of higher level with the item.