Factual error: When the trappers first encounter the Rickarees, the bow cannon is discharged, creating an explosion near the Indians, who promptly turn and ride away. Immediately after, a second shell explodes near them. It would be impossible for a single gunner to sponge out and reload with cartridge and ball in the space of 10 seconds.
Factual error: When the Rickarees encounter the trappers, explosive shells are fired by the boat's cannon. The incident occurs in 1820, when the only weapons firing explosive shells were short-barreled mortars firing in a high arcing trajectory, not flat-trajectory cannons.
Factual error: When Zach and his companion are hunting, Zach shoots a deer. He reloads his rifle with powder and ball, yet never does prime his firing pan, a must with a flintlock. However, when he is surprised by the bear, he discharges the weapon.