Every now and then you will find some gun store that has a box or two of old Norma ammo still on the shelf, or someone at a gunshow who has some...but this getting more rare as time passes. I have noticed over the years, but unfortunately cannot recall what store I last saw some at. (Saw 308 Norma Mag more often. You should be able to neck up that brass too, if you can find some of it.
You are going to spend some time visiting gun stores in every town around you, and on your travels, or calling them up to see what they might have.