qsy-complains-a-lot:

Charleville Mle 1786 hussar carbine

Designed by Gribeauval c.1777 and manufactured in Charleville, France.
17,5mm/.69 caliber, flintlock, saddle ring.

Note the brass pan to avoid unwanted sparks when loading the gun. This shortened and lightened version of the Charleville Mle 1777 musket was used by French light cavalry until around the French Revolution when military firearms were further standardized. The ramming rod appears shorter than the barrel itself, however it is actually stored very far down the stock, which in turn allowed for a short foregrip.