All the rifles used in the film are single shot, M1867 Remington Rolling Blocks. As the model number suggests, they hadn't been invented until 16 years AFTER the the year (1851) the film portrays. All Pistols used are the Colt SAA 1873 (Single Action Army) in various barrel lengths (4.5" - 6.5"). The only pistols available at that time were single shot percussion (cap & ball) and Colt percussion revolvers such as the Colt 1851 Navy.
During a shooting lesson one of the men tells one of the women to "aim low that will make up for the recoil". When shooting a gun the bullet has long left the barrel, before the barrel begins to move in recoil. Aim low and you'll miss low.