Hi guys. I have a bunch of shotshell primers that have been sitting around since my trap shooting days. They are new in the box but are probably 12-15 years old. They were in my garage the whole time. What are the chances that these primers are any good anymore?
I have primers also from the early 90's and full confidence in them. From what I've read even soaking them in oil trying to render them neutral is only a temporary solution, once the oil dries out the primer compound is again active. I have loaded ammo dated 1969 that fires without a problem. I'm sure their are many with ammo from the 50's they are shooting.
You should probably use them up though within the next 40 years.
Just to-day at the range I fired some 22yr. old .38spl. handloads so both the primers and powder were old . They printed in a 2" group at 25yards so they had kept well . If components are kept in cool dry conditions they will last .
Being in the garage all this time they weren't always cool or dry. I live in Wisconsin so they probably got hot, cold, and damp. Are primers sealed well enough by themselves to hold up to this?
Well, find somebody locally who will load up a few cases with these primers, then go out, pop them. If say a random 10 (not all from the same place within the batch) go off without a hitch, I would say they can be assumed good.
__________________ Suppose you were an idiot. And suppose you were a member of Congress. But I repeat myself – Twain.
Shelf life of primers 
