Also depending on which municipality you reside in, regardless whether you inform your neighbours or not, if a complaint is made, you MAY and CAN be charged with discharging a firearm. The cost of that here in Saanich (Victoria BC) is a 100$ fine.
But to add to that, if the call was made either the police or bylaw inforcement would arrive. As far as guns go, I bet it would be the police.
Short answer, if a complaint is made, the police have a duty to investigate. At the end of it all, you MAY have your weapon confiscated.