As I said old rifles were in use, but just think on the numbers.
In 1776 our population was about two million, approximately six hundred thousand adult men, were ten percent of the population rifle owners? Sixty thousand? I doubt it was that high.
by 1790 the population had doubled, and doubled again by 1810, the eve of the war. There was about eight to nine million about three million adult males. If ten percent were rifleman that’s three hundred thousand.
Assuming our high number of sixty thousand rifles in 1776 that’s one in five at the most, if they were all well cared for and all crossed the fall line