Almost 100 police raided 10 homes, arrested 14 people and seized drugs and guns following a 10-month trafficking investigation.
The Springvale-based Divisional Response Unit (DRU) executed warrants at 10 properties in the early hours of Tuesday 17 April as part of Operation Bonito.
Properties targeted included homes in Nourat Place, Cranbourne North, Bellario Circuit and Trainers Way in Clyde North, Bakers Road in Dandenong North and Alexander Avenue in Hallam.
Police seized about 500 grams of methylamphetamine, two litres of GHB, more than 100 prescription pills, a revolver, a shotgun, a rifle, a fully automatic pistol, other prohibited weapons, ammunition and items suspected to be stolen.
They charged a 26-year-old Hallam man with trafficking firearms and a commercial quantity of amphetamines.
Police also charged a 54-year-old Hallam woman for breaching a court order and a 44-year-old Hallam man with possessing a drug of dependence, committing an indictable offence while on bail and driving matters.
They issued a 29-year-old Hallam man with a penalty notice for breaching a bail condition.
Police charged a 26-year-old Cranbourne man with trafficking amphetamines and were to charge a 27-year-old Cranbourne woman with the same crime.
Almost 100 police members from Crime Command, Casey CIU, Greater Dandenong CIU, Southern Metro Crime Team, Frontline Tactical Unit, Special Operations Group, Critical Incident Response Team and the Dog Squad were involved in the warrants.