Barrie police seized drugs and a loaded semi-automatic pistol at a residence in the Mulcaster and Penetang Streets area on Saturday.
They were called to the residence in response to a disturbance and were met by a man with a knife.
He was arrested without incident.
Police say the guy provided a false name, though officers were able to confirm his identity and located a gun in a pouch around his waist.
Several bags of suspected cocaine and fentanyl were also found.
A 29-year-old Barrie man is facing a total of 14 drug and weapons charges.