Ike Clanton is holding a 22 rifle in the botched attack at the railway yard.
At minute 1:30, a thirteen year-old Wyatt (Circa 1861) is shown loading cartridges in a Colt Single Action Army pistol. However, that pistol was not on the market until 1873. During the Civil War, pistols used "Cap & Ball" ammunition, had open-top frames, and took several minutes to reload.