The year is 1767. Ben Franklin returns to his property to find mysterious crates containing 200 Chassepot 1866 rifles and 10,000 of black powder ammunition for them.

Would he, or anyone he knew be able to reverse engineer the rifles and ammunition to put what they find to any practical use? While the Chassepots are more advanced than the arms of his time, they are only one hundred years more so. Would people of the 1760s, being shown an example of a centerfire primed ammunition be able to create their own? (I have no idea if fulminated mercury was known to them, for example). Would they by able to replicate the basics of a single shot breechloader?