Ever wonder why it really was that rifles were so rare in 1775? Was the rifling really that much more expensive to make? Did the ball really fit tightly against the lands as it was being ramrodded in? I've heard a handful of independent reasons, and even given a couple myself as part of the history of the Redcoat target on Saturday morning.
In the 1960's, a gunsmith named Wallace Gusler performed a fascinating feat of "above-ground archaeology" of the manufacturing of the Kentucky Rifle, for a museum town in VA: https://www.flintriflesmith.com/WritingandResearch/Published/wallaceretires_mb.htm
In 1969, this 1-hour documentary of Gusler's shop was filmed, providing fascinating insight into this question:
https://www.youtube.com/watch?v=X_O1-chxAdk