I’ve got some cci 200s from the 70s in a white box left over from my dads reloading endeavors I used them in my early days of reloading and had the occasional click no bang are they any good

If stored properly, they should be. Only one way to find out

I don't think there's anyone here old enough to provide a definitive answer

If you take care me, I love you long time.

MM

I have some old Remingtons in a wooden tray with a cardboard cover like todays primers. Probably from the early 50's maybe.I have three trays of them. Tried few of them and they go bang.

I had 10,000 primers from the 60's and 70's, they all went bang no problem.

I'd chalk up you click no bang to "maybe something else was at work'' as to why they failed, in your early days of reloading.

Put a few in an empty case and try them.

I have some small pistol primers that old. I would expect them to mostly go bang. I have had some primers fail. During the Obama crisis I bought a thousand MagTech primers. I would say 20 out of the thousand didn't pop right or at all.

Last year I used some CCI primers that I bought from Honsport in Honolulu in 1977 or so when I was stationed in Hawaii. Velocities, POI, etc were right with other new CCI primers

How long do primers last?

Simple Question...

Regardless of Brand or Age,

Simple Answer: ONE shot....

Yep and from the time the firing pin hits a live primer it only lasts about 2 milliseconds.

I dump up to 30 into my Lee Auto Prime, and then check that each has priming compound. So far, no empties and no failures.

I have some small rifle primers made by Winchester that have wooden trays. My dad found them in his old stuff when cleaning out. I'll try to get a picture up in a day or 2. I have shot them in a Bee and a K Hornet. They still go bang. Have to be from the 50's or 60's.

I have used primers from the late 40's, 50's and 60's with zero issues.
I still have a few hundred HERTERs primers, that because of current conditions, it appears I will have to use up. I have no issues about using them.
As long they've been properly stored, they'll work.

WB

I've been mixing 70's vintage CCI 200's & 250's with new for years without issue or any clicks.

How long do primers last?
You have to throw them away after you shoot them.

Sorry, I couldn't resist.

You beat me to it.

I bought a bunch of reloading supplies at an estate sale . All were stored in an outside metal storage shed . Powder , primers etc. The primers were old Remington in the wood trays. I just set them aside figuring they were no good. A couple years later I decided to try them. I ran the ammo over my chrono . Old primer vs new primer. The difference in velocity was insignificant.