Other mistake: Throughout most of the film, Mattie Ross' gun is correctly shown to be a Colt's Dragoon .44 caliber revolver. However, in the scene where Tom Chaney is looking down at her from the top of the well into which she had fallen, the gun in his hand is a Colt's Model 1860 Army. Presumably, when he, too falls into the well after being shot by Marshall Cogburn, the gun goes with him. When Cogburn retrieves the weapon before helping Mattie out of the pit, the gun is once more a Colt's Dragoon.
Suggested correction: The pistol used throughout True Grit is a Colt Walker .44, not the later-made Colt Dragoon, and the pistol in the scene of Chaney looking down at Mattie is the same pistol. If you looked closely at the loading lever you should have seen this. Also, he is looking down into a snake den, not a "well."
