I read an article a long time ago about someone using a tumbler to polish old loaded rounds that he had for a long time. Someone advised against it because if you (shake) them to long they could rub coating off the powder and change the burn rate of that powder. I just wouldn't do it to long...
If I remember correctly Brian litz said that "after powder, primers were the second thing that affected fps the most" so the change on es and sd would be evident on SOME rifles.
Had the same thing happen to me with WLR primers. Contacted winchester and they gave no reply back with the 2 emails I sent. Went to cci. This happened with 3 different rifles. Same batch of primers.
Disposed of the rest. No more WLR.