Goofs

When the log cabin is attacked Jane is told by Dan to take cover - when she is shown ducking behind a bed she suddenly has a hat on she did not wear before.

After shooting Mr. Bishop four times Jane still has at least three bullets left in the revolver, as can be seen in the closeup.

Jane is seen practicing with her revolver, which switches back and forth between a Walker and a Single Action Army.

After missing her target horribly while learning to shoot a pistol, Jane picks up a rifle to demonstrate that she can shoot that type of firearm well. Jane then proceeds to shoot the handle off of an ax. No settler out in the middle of nowhere would shoot the handle off of a much needed and precious implement such as an ax just to prove a point.

It's just a stick and it looks to be a replacement for the last stick/handle. The precious part of is the steel axehead.

When Dan Frost first meets Colin McCann in his office, there is a close-up shot of Ewan McGregor's face with a white liquid visible below his mustache. Presumably the glue used to affix it to his face.

Spirit gum is used to glue mustaches and it dries clear. The white seen below his mustache is his upper lip highlighted by the light from the window.

Early in the film, Jane says she is looking for gunslinger, the term gunslinger was not used until the 1920's.