An Afghanistan war veteran who shot up a BMW dealership in a drunken rage is facing at least four years in prison.

Corporal Jonathan Laporte shot up his own home and two neighbours' cars before blasting his way into a family-owned BMW dealership in Ottawa, Canada in the early hours of the morning.

He fired into an X5 SUV in the showroom and a 3-Series which was parked in the delivery bay ready to handover to its buyer.

No-one was present in the dealership at the time, reported the Ottawa Citizen.

His rampage came just hours after he was released by Ottawa police who'd charged him in connection with assaults on three men.

Laporte pleaded guilty to firearms offences, three assault charges and faces a statutory minimum of four years' prison but plans to challenge the sentence.