Supplies of military barrels have pretty much dried up in Canada,altho folks do have the odd one in their stashes. I've bought a couple of take-offs from folk who replaced them with .308 barrels.
I used to buy quite a few used barrels from the US before the barbed wire went up and these were always a bit of a crapshoot on extent of wear. Good idea to visit gunshows with throat erosion and muzzle wear gauges in your pocket.
Buying a new .308 or .30-06 commercial barrel from an importer is probably the best alternative,even tho wait times may be long. These will most often need the shoulder turned down a bit for correct indexing. Finish reaming to set up headspace is also required.