OK: character concept. Shitty younger son, no-one likes him. Loves to fuck around with chemistry and science it up, but knows that if shit hits the fan and he's just a scientist he is going to get murdered for his place in the line of succession. So he joins the army, gets promoted to Major or something, still fucking around with chemistry. A few months before the game starts, he discovers he can make shitty black powder [he dreams of one day making a smokeless propellant, but that is not going to happen any time soon], and has been working on a breech-loading, chassepot-esque rifle for his Battalion-equivalent [they used to be pikemen or something]. Cue the death of the crown prince, and now he has to navigate politics long enough to get someone to make his guns and ammo for him, while not tipping off his brothers and sisters who would like nothing more than to murder him and take his revolutionary, if somewhat half-baked, weapons away from him and use them to conquer things and take the throne.

Thanks to the evident quality of metalwork and gunsmithing, it won't be that hard for a talented individual to whip a breech-loading rifle up, though obviously since they've nevuh been done befo', things are going to be a little jury-rigged.