ok, well, I no longer have say in how they are going to run this event, so i am hesitant to say what the rules are. Especially seeing as how they have changed up to there new fps limits and range and stuff.
Last year is was semi only, with like a 360fps cap, and i believe they allowed the gun to pass with a .25 instead of a .2 for that specific field. But with the new changes, who knows if it will be the same or different. Best bet would be to start a thread over there asking if they are doing it, and what the rules this year will be. ( I am fairly certain they are doing it )
Observationaly,
last year a few ran springers, ( shottys and pistols, there were no snipers allowed ) but most ran there normal every day gun, some had a few weaker guns they they do not field much, others ran single or duel pistols and did well.
as far as it being close quarters, well, yeah, its sometimes close quarters, but allot of fighting went on at a range better then 30 foot, so that really isn't close like trying to sweep a building is close.
guess what i am saying here is, very few people used other then there normal play gun. You will regret not bringing you best qualifying gun, don't make the mistake of saying well, i know trigger response, or range or accuracy of this gun is bad, but it shouldnt matter at close quarters.
I will probably go down at least once if they run on a sunday, it would be nice to get a group of us, or at least my Squad together for a off home field game.