Mill Park Embona detectives arrested a man and located multiple firearms during warrants in Doreen on June 20.
Police responded to reports of a gunshot that struck a vehicle on Bridge Inn Road in Doreen on May 28.
The male driver and female passenger were not injured during the incident.
Police searched addresses in Doreen on Tuesday, where they allegedly found nine firearms, ammunition and other prohibited weapons including a sword, knuckle dusters and a butterfly knife. All items were seized.
A man, 47, was arrested and has been charged with non-prohibited person possessing firearms, possessing prohibited weapons and possessing ammunition without a licence.
He has been bailed to appear in Heidelberg Magistrates’ Court on November 15.