I'm interested in the same sort of thing for a similar reason. One of my 4-great grandfathers was Capt. John Autry of the Wilkes County, Georgia, Patriot Militia. John was from what is now Sampson County, NC and moved onto the Ceded Lands in Georgia in 1773. After he was killed by Creek Indians in 1788 his son John, Jr., my 3-great grandfather, returned to Sampson County, NC, then moved to Cumberland County, NC, then finally back to Georgia. The Southern militiamen were generally riflemen, and pension records of soldiers under John Autry's command specifically said that Captain Autry's company was a company of riflemen. There is a book on NC rifles and by careful reading of it I decided that riflemaking there was in its barest infancy at the time and that it was more likely in the Revolutionary period that a North Carolinian or Georgian would have carried a rifle made further north... Pennsylvania, Virginia or Maryland. The Wilkes County Georgia militiamen were among what was known, however, as the Georgia refugees. When the British fleet sailed south and took Savannah and occupied Georgia, these Georgians packed up their families and evacuated them enmasse "overmountain" to what is now Tennessee, then they continued to fight in the Carolinas till the British left and they could take Georgia back from the Tories. So... there is also some possibility of them using Tennessee rifles.
By and large the war in the Carolinas and Georgia was entirely different than the war further north. I think you might enjoy reading _A Devil of a Whipping: The Battle of Cowpens_ and possibly also _Longrifles of North Carolina_... though I'll warn that the author doesn't really find any North Carolina rifles going back to the Revolution.