The priming compound will eventually deteriorate no matter whether it's sealed or not.
45 years, may be asking a bit much of it.
There's a good reason this stuff goes out as surplus. It usually has a best before date that we don't usually see.
Sometimes that stuff is released because of erratic performances when tested or they might just have a standard shelf life.
In reality, corrosive primed ammo usually lasts longer and can handle wide temperature swings. They certainly aren't cheaper to produce, so there had to be a reason the Soviets stuck with it for so long.
I had several thousand rounds of 8x57 that was as new in the original wooden crates, all dated 1938. Lovely stuff. When I packed it away, it was fine and quite accurate. That was 1972. It was cheap like borsht, so I bought 100,000 rounds. IIRC, it ran around 3 cents a round, in that quantity.
Over the next 10 years, I sold that stuff off except for 5000 rounds. The machine gun guys loved it and I made some very decent profits on it.
About 5 years ago, I broke some of it out to give it a run with a couple of Mausers I like to shoot.
Just keep in mind, since I've owned this ammo, it was never stored above 25C or below 10C.
It should have been just as good as the day it was loaded.
Nope, right from the first shot it was obvious something was wrong. Hangfire.
Next shot was fine, other than it was off the target. The rest of the mag, gave me a group about 25cm in diameter. Same thing happened with the next group. The second rifle had similar reactions.
I pulled all of the bullets and kept the powder.
I tried reloading the cases with 3031 and had similar issues with accuracy and of course hangfires.
Later, I recycled the powder into some commercial cases with new primers. 100 rounds and not a hangfire and the stuff was reasonably accurate. Around 2 inches at 100m, which is consistent with the accuracy of both rifles under normal circumstances.
I've had similar issues with 303 British, both with corrosive and non corrosive primers.
Then again, I have a bunch of mid thirties dated 7.62x54 and so far, it's just as good as the day it was made.
It's all luck of the draw.
IMHO, if you're storing away some ammo for emergency purposes, spend the extra dollar and buy newly manufactured ammo that you can trust for the next 50 years. Your life may depend on it. Taking the chance just to save a couple of hundred dollars just seems to be counter productive.
