I've used both powder and primers that was over 30 years old and it chronographed the same as a new lot I tried.
If it has been stored dry and cool, it will be okay.
When you open it, if you get an acrid smell and some reddish tinge around the lid, it will need chronographing to be sure it is still decent.
if however, you get that "nice ether smell", she's goodtogo!
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