ORIGINAL: cyclone
Are you using oil? Regular gun oil or other petroleum products will cause black powder/pyrodex/777 to misfire or hang. Best to use bore butter or plain ole crisco..and go light...
Possibly, unless you remove sythetic or petroleum based lubes prior to loading and shooting. Synthetic lubes (Clenzoil & Otis Ultra-Bore) here for long term storage. Clenzoil since the late 60's/early 70's.