Very well shaped and good architecture from what I can tell. Mountain rifle, likely southern, is about as exact as I can get based on what's there, but there's a few clues that might narrow it a little more like what CCF and Tanselman said.
Two holes for lock nails doesn't guarantee it started out Flint, but it makes that worth considering. To me the styling (especially the lower, softer nosed comb) looks 1820-30s more than later, but I could be wrong, and some places older fashions persist longer than others. Just observations for the discussion, not an expert opinion.