Unless Illinois law SPECIFICALLY states differently - shotgun plugs are necessary only for hunting. For skeet and trap it should make no difference whether the gun is plugged or unplugged.
Yes, it is legal. However, it is illegal to hunt migratory birds with a shotgun that holds more than 3 shells (2 in magazine, 1 in chamber). That is why many "bird guns" come already plugged. All self defense shotguns have the plug removed. I believe in most states you can hunt deer and other game with unplugged shotguns.
It can be left plugged in
Monitor is not plugged in or monitor is not plugged in to computer
Plugged. Our boat had a hole, so we plugged it.
It is plugged to the RAM slot.
Plugged in Permanent was created in 1996.
Plugged fuel filter? Plugged air filter? Plugged catalytic converter?
Plugged air filter? Plugged fuel filter? Plugged catalytic converter?
The Girl Who Was Plugged In was created in 1973-10.
Plugged In - album - was created in 1993-09.
Plugged fuel filter? Plugged air filter? Plugged catalytic converter?