I keep three 8# cans and a couple 3# cans (all 1995 vintage Winchester powder, W296,W231, Superlite, Super Field AA) laying on their sides in a 4' wide office filing cabinet with a row of 1# cans standing upright at the back of the drawer. Noticed a never opened 1# plastic can of VV-N350 (prob. 2009-2011 vintage) left a "rusty" spot on the bottom of the cabinet where it was sitting and upon closer inspection the can had the rust powder all over it. What's strange is the top of the 8# W231 metal can which was adjacent to the VV appears all rusty. Thought initially the W231 had gone bad but the powder was almost odor free and looked great. It appears when the VV started deteriorating, it off gassed and coated the top of the W231 with red powder. Pulled the sealing tab off the VV and a quick sniff of it almost crossed my eyeballs. It surprised me the VV powder, manufactured ~13 years later than the WW, went bad this quick, while all of the older WW powders passed the visual and smell test. What started me looking was an article in a gun mag a couple months ago about checking one's older powders for deterioration. I had been complacent about it as all my powders have been kept in air conditioning since purchase. As Chuck Berry said, It goes to show you never can tell.