You also have to lube your balls before shooting as they create more friction than standard balls.great idea and if i could i would, but remember that chrono-ing with reballs will not mean you will shoot paint at the same fps on the field, due to reballs being smaller in bore (usually) meaning more air escapes around the ball and therefore the ball travels slower, so for example if your shooting reballs at 295fps be aware that when you walk on to that field with paint in your gun you could be shooting illegaly.
as cook$ said, safety first!
get Lizards. Then put a sign up saying 'I breed Lizards'Naaa we have police choppers that fly round looking for heat sources in the attics in the UK.
One guys house got raided by the police only last month due to this. Problem was it was a faulty air con unit creating the heat