When Harlan takes Lonnie shooting, he uses a gun that takes 6 rounds. After shooting all six out of one and supposedly shooting four from the other, he offers the gun to Lonnie and asks, "Do you want the last two?" However, five shots from the second gun can clearly be heard before he makes the offer.
When Harlan and Lonnie are chased away from the campfire, Harlan's mustache is missing in the next scene as they enter the old west town. It is missing from the rest of the film, even though there has been no time for him to shave it off.