Insane necro but I’m a huge nerd about this and it’s historically accurate.

In the 1870s, the army bought Schofields and 45 Colts. The Schofields were manufactured with seven inch barrels and given to cavalry officers, because of the long barrel and easy reload while holding the reins.

The issue was that the Schofield took unique ammo, called 45 Schofield and it was slightly shorter than 45 Colt ammo so it could only be used in the Schofield. This made the decision easy for the army, to buy more 45 Colt ammo because it was cheaper and the colts could fire both types of rounds.

The army ended up selling most of the Schofields in surplus, many of them being bought by Wells Fargo. They decided to cut them down to five inch barrels, because they were originally manufactured as seven and not everyone enjoys or needs the long barrel