Patrick Deegan, 29, was also given three years probation and is to get counselling. With time served, he will be behind bars for roughly 10 months.
Deegan pleaded guilty to uttering death threats, possession of unauthorized firearms and two counts of breaching conditions in January.
He made the threat in an email to the Calgary Fire department.
"There is going to be a machine gun attack at the Calgary Stampede this year," the email read. "Two MG-52s rated at 1800 rpm. There will be over 1,000+ casualties. These machine guns can fire 1,000 rounds before malfunction."
The email prompted a police investigation that led officers to search the homes and cars of Deegan's parents and girlfriend in June 2013.
Police found two improperly stored semi-automatic rifles and one hunting rifle at his parent's house.
At the time, Deegan was on a 12-month peace bond for a violent domestic incident. One of the conditions of the bond was that he wasn't allowed to purchase or possess firearms.