The 1970's TV series "Centennial" did a tolerable job @ accurately portraying the early fur-trapping era in the initial episodes with Robert Conrad and Richard Chamberlain.
Not a movie, but the series, "Into the Wild Frontier" may go a long way in keeping the spirit of traditional muzzleloading going with a new generation...I've already told my 6 y/o grandson the story of Hugh Glass and the grizzly bear and John Colter, and by chance we did a search looking for more info, and the series popped up - he's watched the one on John Colter over and over, and when he comes over, he asks to watch, "John Colter's run"...up next is the story of Jedediah Smith. Don't know the armorer(s) supplying the flintlocks and period accoutrements for this series, but they do a good job in accurately representing the fur-trapping period...