Factual error: The movie is set in 1843-44, when the rest of the world is still using cap and ball weapons, yet Ranger captain Jake Cutter is wielding a gunbelt with filled cartridge loops and a colt six-gun.
Factual error: The rifles that Jake Cutter has Paul Regret dig up are Henry repeaters, or possibly 1866 Winchesters. Either way weapons unavailable in the period depicted in the movie.
Factual error: While giving Jake and Regret a tour of his hideout, the comanchero leader points out his powder mill, claiming that he gets his nitrates from his own mines, and the saltpeter from deposits to the south. If he has nitrate mines, he has no need of saltpeter.they are the same ingredient for black powder, potassium nitrate.
Factual error: Tully Crow dies with a model 1858 Remington New Model Army revolver in his hand, quite a feat in the year 1843.
Factual error: Jake questions a prisoner who was recently released from Yuma Territorial Prison, a prison that would not have been constructed until 1876, 33 years in the future. As a matter of fact, the area where the town and prison would be built was, at the time period of the movie, still part of Mexico.
Factual error: Melinda tells Paul Regret that her husband was killed 4 years ago, at the battle of San Jacinto. Since she is living in the year 1843, that battle would have taken place over 7 years ago.
Continuity mistake: When Jake Cutter and Paul Regret ride into the ranch yard, two of the victims are hanging upside down over the gate. In the close-up, there are three arrows imbedded in the gate posts. In the far shots, the arrows are not present.
Factual error: After Regret is sworn in as a Texas Ranger, he and Jake head out in the wagon with Tobe as a scout. Tobe pulls out a pair of binoculars to survey the route, but in 1843, binoculars were not yet invented.