Primer Storage

[260 Rem]

After a month in Palm Springs I returned to break-in a new 308 Win barrel with 8 cartridges I loaded just before leaving. They all went bang ... I loaded up a couple of groups the next morning, off to the Range ....every one failed to fire. Took them apart, reloaded from a different pack of primers (from the same brick), back to the Range ... clicks. Today tried some loads left over from a rifle I sold and they all went bang. No doubt something that happened while they were in storage killed the primers...the (partial) brick was stored in a metal container in a cool room while I was away. I have stored primers in the same location for years. Never had a problem before. CCI BR-2’s. Any ideas?