what rule are you talking about? I know you can't rig a model to shoot a projectile and you would loose your liability insurance if you did this at a sanctioned field. If you were say at a buddys ranch and started firing at your model there is nothing to stop you. A bunch of buddys get together once or twice a year at a ranch and shoot a couple trainers and or a couple eletric zagi wings out of the sky with shotguns and have been doing so for several years. I guess the adage is if it doesn't disturb the cows who cares but then again someone will belt out an old, that's irrresposible, remark. When done right and with some common sense it's not much diferant than shooting clays. just bigger, noiser and allot more fun to shoot at.