I just loaded a couple of batches with 23 year old primers stored in somebody’s uninsulated garage and they worked fine.

Update 11/14/2020
Thanks everyone for your input. This week after spending 3 hours getting my reloading equipment set up,cleaned and working again I was able to load 80 rounds of test loads.
Went to the range today and tested them. After all my components sitting over 20 years everything fired with no problems.
Next week we will load more rounds and after I test some of them I will load what ever I have left in components.
Thanks everyone again

My brother who is the ultimate scrounger picks up odd lots of reloading supplies frequently. He has an old hardcover book “Phillip B Sharpe’s complete guide to hand loading” from the 1940’s which has proved invaluable. He has at times gotten sealed cans of powder that were discontinued in the 1940’s that we used in conjunction with the old obsolete data found in Sharpe’s book that worked just fine.

Thanks everyone for all the great information.
So far all of my reloads are going bang, so far so good.

Did Y'all know that milk rarely lasts more than a couple of weeks? The same for uncured meat. So I guess its where the idea came from that things don't last. Oh, apples rot, too. Our fridge has "food" in it that could have been brought over by old Chris Columbus. Yet we know that fruit cake lasts centuries. One theory is that there may only be one fruit cake or one batch of them and it just gets packed away with the ornaments each year. No one has ever tasted it.

Not long ago (ok, maybe a couple of years, I csn't remember much these days) a guy had a "reloading kit" for a .32-20. It included brass, bullets and primers. It was cheap enough that I bought it. The primers are probably from the 1950s. Funny looking box, the old wood one. I just hope they're not from the 19-teens and corrosive. Probably like gold these days. I just can't figure out why the seller didn't include powder - wait, I know, it goes bad?

As an Ex-Floridian, I kinda had to laugh about how stuff should be stored in a "cool dry location" when the OP lives South of the Mouse.

I'm currently using some powder I purchased in 1970. It's been outside in a pickup truck shell at -40 degrees Fahrenheit for 2-1/2 weeks straight and stored in a garage at up to 130 or 140 degrees for around 30 years.

I've loaded .410s with it and with brand new powder of the same type and shot one after the other at clay target games and see no difference whatsoever.

I've also got some primers from 1970 that went through the same temps and I periodically take out a couple and try them. They go bang every time.

A lot of people here in Arizona store their powder and primers in storage sheds in their yards and it's around 140 degrees all summer long.

I wouldn't worry about it at all.

quote:

Originally posted by MikeinNC:
Heat is what damages powders and primers

Exactly.

I had over 10,000 Winchester Large pistol primers stored in a non-climate controlled building for several years. When I finally got around to loading some .45 ACP, several out of each 100 would not fire.
Lesson learned. Now, everything is stored in a climate controlled area.
Powder, Primers and cast lead bullets.

The year before last, I bought up a bunch of primers that were at a local gun store. They'd taken the primers in trade apparently, and were clearly old. The price was right, so I bought them and loaded them all up. Because decap/resize in one operation and toss the brass in one container, then prime and toss it it another, the primed brass were mixed; several types of primers.

I began having issues at the range and at steel shoots, and quickly noted it was the new primers. At first, I thought perhaps they weren't seated properly, then theorized about hard primers, but they were seated to the same depth, and they dented the same. Just didn't go off at times. I finally segregated them (and used them for range ammunition, where they continued to have a higher incidence of failures.

I do not know their storage condition, so can't comment on what kind of exposure, duration, or age, caused the problems. They did appear fairly old. There were five thousand, or so. It's the only batch of primers I've used that have had that problem.