It was said months ago that the non availability of Federal large rifle magnum primers was most likely due to federal using more of them in their own ammunition. The demand for their ammo has slowed due to most hunting seasons being over. That may be why they are now available many places.Lohman Arms always shows they have them in stock, but never do.
I picked up 10K of 215m primers last month from Mid-South with free hazmat. Cabela's also had them at same time.