How long can primers be stored? This is given that the storage conditions are proper ie, warm, dry

I have some old(+/- 20 years) RWS that I've been using up for plinking. I've had a number of duds although the primer has a nice, deep indentation. On some the second try produced a fire. Also, the loads shoot ugly groups. The load is .30-06, 165 Speer spitzer, 58 gr IMR4350. This load has alway proven accurate in any .30-06 I've owned.

Mauser, I think you left out an important variable in your question...that is what was the compound and quality of the primer construction in the first place?

I have seen primers last that long and work OK, and am in fact loading right now with some about that old. But I live in the desert southwest United States. Your idea of warm and dry are a LOT different from our idea of warm and dry.

Anyway, it sounds like these RWS primers are ready for the trash can. Sorry. I hate to waste loading stuff so I know how you feel.

It just occurred to me that I believe the US Military has some guidelines about how long it will store loaded ammo before it scraps it. Does anyone know what the military standards are.
(Of course we are talking LOADED ammo here.)

Good point, Pecos

I live on the wet coast of British Columbia within spittin distance of the ocean so our humidities stay pretty high and hot is 22 degrees C.

The primers are going in the garbage.

I just finished using up some CCI Large and Small Pistol primers that were originally purchased in June and July of 1975...

They work flawlessly...but I keep mine cool and dry, away from solvents and cleaning supplies and in original packing.

Why did I have them around so long? Because I ordered 50,000 at a time.

Actually, when I think about it, I got these primers off a guy about 5 years ago so I don't really know there storage history. Anyway, they're gone.

There's a fundamental difference in primers that are stored for reloading and primers that are sitting in loaded ammo.

Loaded ammo is pretty water tight -- not perfectly water tight, but pretty close. I have Turk Mauser ammo from the 1940's that shoots just fine. Who know's where it's been? The bandoleers seem to have integrity -- not rotted or discolored like they've gotten wet. I've had Equadoran Mauser ammo that was inconsistent . . . about every 10th round needed two or three strikes on the primer. The stuff is circa 1940's

But old primers that have been sitting around in boxes . . . Not worth much. I've got retailers battling to sell me primers at $17.90 / 1000 -- Federal Small Rifle #205. With the money that goes into ammo, fresh primers are a good investment.