I've been thinking about something like this for a many years. To me, the Plainsmen period runs from about 1855 to the late 1870s, although I can see where that time frame might create a lot of problems in real-time application. The 1840 to 1860s period would probably work better. I was thinking maybe 1840 to 1869, which was more or less the era of the percussion ignition. I'd also like to see an emphasis on historical accuracy. No flintlocks, and no firearms produced after 1870, and all firearms must be common to the time, and to the area west of the Mississippi. Black powder (or substitute) only, even for cartridge firearms, and in order to make it as fair for single-shot pistols as it is for revolvers, not to mention enhancing the shooting area – NO TIMERS. Also no gun carts or other modern items.
What I've always envisioned was of a bunch of frontiersmen coming together in an encampment of tents and tipis somewhere on the plains and spending a few days of camaraderie and shooting matches. Kind of like what I've seen in photos and heard about in a NCOWS primitive camp. This could be done in the imagination and with postal matches for a while, but who knows what might develop down the road.
I've emailed Marshal Hollaway asking about the possibility of getting a forum dedicated to this period. I haven't heard back from him yet, but I know he's a busy man. I'll write him again today.
Let me know what you think.