In the initial civil war battle scenes Anse Hatifield encounters a young wounded soldier about to kill himself. The soldier's revolver is a cartridge conversion ( a percussion, cap & ball revolver converted to accept metallic cartridges). Such conversions had not yet been perfected during the civil war.
The mountains sometimes shown in the background have jagged peaks that are found in the Rocky Mountains. The mountains of West Virginia and Kentucky have rounded peaks like the rest of the Appalachian Mountains owing to millions of years of glaciers advancing and retreating and eons of erosion. The much younger Rockies have jagged peaks because they have not yet gone through the many years of erosion.
When Anse Hatfield is fishing with his son he draws his revolver menacingly. The revolver is unloaded.
During the attack on Randle McCoy's cabin the thumb piece of the magazine follower of Uncle Jimmy Vance's Henry rifle is in the rearward position against the receiver. The means the rifle is unloaded.