Small quantities can also be used for lab testing purposes. The FBI keeps a library of all known ammunition sold in the US for comparison purposes. A bullet fragment from a crime scene or dead body can be traced to a manufacturer by chemical analysis.
I would be interested in knowing what .45 Colt ammo they are purchasing.
The so called cowboy load is relatively mild. Shooting it is easier than shooting .38’s.
But if you go to Cor-Bon or Buffalo Bore for their high powered loads, you get ammo that will stop a bear or moose.
What gr. and FPS they are purchasing will tell you a lot.