I have some old 45-70 shells from the early 1900s---They still go bang and accurate out of my Trapdoor----Have you ever wonder why,if found a WW1 or WW2 ammo or bomb,how the say stay clear----I have primers from the early 60s that I still use for my practice loads and still no misfire---Don't worry---hoard them---I just bought 5000 Win primers @ $150.00 amd told the price will go up if you can get [email protected]
I just finished up a batch of the old Remington *97 primers year before last. I quit shooting trap in 1973 and I purchased them sometime before that. My Red Dot powder had faded out to a very light pink over the years, but both powder and primers worked perfectly when I started back to shooting in 2009 when my grandson got interested in shooting trap. Storage conditions I have is a cool, dry basement that didn't have much over 15 - 20 degrees of temperature change during the year.
I rely on 70 yr old primers every grouse season. Grouse aren't easy to come by so it pays to have confidence in your ammo. All I hunt with are paper factory loads from the 1950's and they never fail to go bang.
However, roll-crimped paper factories date mostly from before WWII and I found them way too unreliable. I think all the small arms research for the war effort made a huge stride in primer reliability.
Like a lot of others, I have flats of target loads that are 15+ years old and I wouldn't hesitate to use them in a shootoff.
I have several hundred CCI 209's from early 70's. I'm not sure where they were stored over the years but I won't use them any more. Noticed they really smelled bad after firing, majority of them worked fine. Had 3 though that were weak, flame out the barrel and from the port, weak sounding. That's enough for me to not use any more, at least in competition.
Heck, I've still got some Alcan 209 Primers from the mid 70's and they fire
just like they should. I tried a few the other day just to be sure. If I remember right, the plant was destroyed in a fire or something in the mid 70's. They have been on the shelf ever since.