If you play on Sunday the 11th, $5 from admission, and $1 from BBs, will be donated to the Royal Canadian Legion.
I'm going to be there, and plan to stay until closing. Sunday's a good a day as any for a Mississauga meet up. =P
Edit: Missed ydube's post. I'm pretty sure they'll let you use the rifle on the range if it's over 350. I'd give them a quick call before hand.