Haymaker,
Chantilly would be the one to answer specific details, but for the most part, a GAF Muster shoot is set up as a two-gun (NCOWS "Working Cowboy" Category - one pistol, one rifle) match. Most stages involve reloads on the clock of either weapon, sometimes both. If a stage calls for some other weapon, like a shotgun or single-shot, it is usually provided, along with ammo as a staged gun. Shooters wear uniforms of their personna, whether Civil War, Indian Wars, Span-Am War, or ANY Victorian-era military soldier ( British, Boer, Spanish, French Foreign Legion, Native American - Zulu? [nope - no assegais ]) . You could be militia, scout or a partisan, if a lack of uniform is a problem. GAF allows any military sidearm in our tiime period (approx. 1850-1900) including double-action pistols. Match rifles are normally SASS or NCOWS lever actions (true, not totally military in most cases), but after the military "battle rifle" (Trapdoors, Krags, etc., depending on persona) demo at the last GAF Muster, a separate class for that is being considered, but I don't know if Chantilly is considering that for this upcoming one.
I hope I gave you the bare-bones basics. If I am in error, anyone out there set both Haymaker and me straight. I had a blast at the last Muster, and am glad we are having more of these "Regional" shoots. I'm looking forward to being up in Topeka this spring, if my school schedule allows it.
GG