Mattie Ross (Hailee Steinfeld) carries her father's Colt Dragoon, as is described in Portis' book. The gun used in the film is an actual percussion Dragoon, while the 1969 film used a cartridge-converted Colt Walker. It can be surmised that the Walker was used due to its even more imposing size in contrast to Mattie's small stature. But the adherence to the source material in this version is much appreciated. In some scenes, Rooster is seen to be using a Dragoon as well, instead of the Single Action Army and his "Navy Sixes".
US Marshal Reuben J. "Rooster" Cogburn (Jeff Bridges) carries a pair of Colt 1851 Navy revolvers in holsters that fit over his saddle horn. He refers to them in the movie as his "Navy sixes." He uses them both in his famous charge at the end.
Rooster also carries a Single Action Army of "Cavalry" length. In the novel it was stated that Rooster's "belt gun" was a .44-40, the same caliber as his Winchester. La Boeuf (Matt Damon) carries a Single Action Army with fancy carved ivory grips.
A 12 Gauge Double Barreled Shotgun is carried by a passing Native American who fires it off screen to signal that they are being followed. One is also carried by one of the Parmalee brothers of "Lucky" Ned Pepper's (Barry Pepper) gang.
La Boeuf (Matt Damon) uses a Sharps 1874 Cavalry Carbine throughout the film. Mattie is later seen using the Sharps. It is a weapon of uncanny power and precision.
