Heavy BBs (.28s) and a good-consistant hop-up, you can put all the rounds onto a dinner plate at 40 yards (120 feet).
I'd had single-shot hits on players out to 50-60 yards with an AEG, but those are pretty damn rare.
P.S. White_Knight is the guy for AV'ing in the Victoria Region. SIR are awesome guys to game with, your in a good place for this sport.