I have some IMR powder that I believe was purchased in the early to mid 1990s and it is a metal can similar to the smaller (32oz?) metal cans (rectangular) that turpentine and boiled linseed oil used to come in.
Wow, $3.85 a pound!!A friend gave me these not too long ago. Both unopened. It's been a bit since powder was that cheap! I'll open them and try some loads when I'm out of everything else. The cans are dusty but no rust to speak of.View attachment 135923