Howdy
There are a few different organizations that promote Cowboy Action Shooting, but the biggest one, the one I belong to, is the Single Action Shooting Society (SASS). The guns we use are representative of those used in the Old West from 1860 to 1899. However, SASS is not historical recreation, it is a shooting sport using old guns, so there are a few liberties taken. For instance, when SASS started in 1987, there were not as many Italian replica revolvers available as there are now, so for those who could not afford a Colt, a Ruger Blackhawk was a legal revolver, and still is, although they are restricted to a few categories. Likewise with ammo, plastic shotgun hulls are perfectly acceptable. We go through a lot of ammo, and like I said earlier I don't want to spend the time and money cranking out a few shotgun shells with brass hulls when I can mass produce rounds with plastic hulls on my old MEC Jr. I do have a friend who reloads Federal paper hulls, and he gave me a few a while ago to mess around with, but I have not done anything about it. I'm very happy cranking out my Black Powder loads in plastic STS hulls on my old MEC Jr.