I recently opened a sealed can of IMR 4064 of undetermined age, but probably at least 10 years old. When filling the trickler and powder measure and even when filling a case, a very fine yellowish dust is noted. The powder granules look to be normal size and not like they had been run through a ball mill or something indicating excessive handling. I loaded up a couple of test rounds and no signs of undue pressure and load seemed right on par with published info. Any ideas about the dust?
Thanks,
BJB

I have several cans of IMR 4060 that's probably 10 years old as well and I've never seen the yellowish dust you mention. Mine has been stored in cool, dry conditions; maybe the type of storage makes a difference.

In my experience, if powder has deteriorated to an unsafe condition you will know it is bad by the smell before you can see it. Its hard to describe but you will know it immediately.

By sealed do you mean there was a foil stuck over the screw cap pour spout?

I had a bad can of IMR powder once. IIRC it was 4198. When I peeled off the foil seal a red dust wafted up. Also, all the kernels of powder were the same red color; not the usual dark gray\black. And it had an acrid odor about it. As I had misplaced the sales receipt, I spread it on the lawn as fertilizer and bought another can from a different retailer.

To me, it wasn't worth the aggravation to work up a load with a lot of powder which WOULD continue to deteriorate, perhaps very quickly.

Hodgdon might give you credit if you can produce a lot number from your can. Hodgdon distributes IMR gunpowders. Good luck.

By sealed I meant the can was sealed at the factory and unopened until I broke the seal a couple of weeks ago.
BJB