Paintball, fish and Indy cars...
When ever a walk-on shows up with a super gun I will remind him (or her) a number of times that I don't allow sustained or high rate of fire. The player will invariable test my limits, laying out a nine or ten ball string at the start of the first game and I will remind him that three is plenty. If they are real ballsy they might try it one more time but in most cases they get my point and behave. On rare occasions I'll have someone complain or try to argue and I'll throw my "You have brought an Indy car to a go kart track" analogy. I don't care for big fish in my little pond.
What I find most interesting is the players that complain the loudest, the ones that want to rip a newbie or light up a young gun never take me up on my invite to come play with Team 120 during open practice. The team players all have Indy car guns, 13+ balls per second and play up close and personal paintball. Maybe little sharks don't feel comfortable swimming with big sharks.