If we use sasco, we could utilize arnbands, on both arms, and ask that everyone try to bring some binoculars, so they can attempt to verify that they are looking at airsoft players, not real smugglers. You can use all one color, for simplicity, since all we would need them for, is to identify whether they are an airsoft threat, or real threat, or something like white (civilian), green (smugglers), and blue ("border patrol") armbands. Also, for the civilians, you could set it up so when you are border patrol, you turn into a civilian when you get hit, and the person who has been civilian the longest gets to go to border patrol. This would work better if civvies were invulnerable, or have it *kind of* like freeze tag, so if they get hit, they can only walk, not run, for 3 minutes. One problem would be that you would probably never get anything done, because you're cycling through people too fast.
Another idea would be to have everyone draw a number from a hat, and change people out every hour, to keep it as fair as possible.
Instead of doing only shotgun/pistols for civilians, I'd say let them use any medium/close range weapon, but not sniper rifles (wouldn't be smart anyways, as that would slow everyone down.)
Also, I'd suggest having someone be overwatch, with high power binoculars, so they can scout for, and report any potential dangers, or if the real Border Patrol comes to investigate what is going on. If we do this, I would have the person on the big hill at Sasco, so they can watch over everything. If they have a camera with a higher power lens, they could also photograph the game (If I had the film, I'd offer to do that).
This is definitely an op that if you wish to play it at Sasco, you will have to organize it EXTREMELY well, in order to keep potential dangers to a minimum. Possibly even inform Border Patrol that there is an airsoft game going on in the area, so they don't have to worry as much, when they see a large group of people with guns.
~Brian