I recently got a rifle from an aging friend. It's a large wildcat he had built for an elk hunt that never happened but he kept the gun and loved it anyway. I got the rifle (minus the scope), custom dies, leftover powder, and 200+ loaded rounds and a few handfuls of fired brass.
I shot a few rounds of his handloads and about half of them popped the primers out... after doing some digging and comparing I found his handloads to be a bit... spicy... so for several reasons, I decided to pull down all the loaded rounds.
Here's the problem, most of the loaded rounds that I've pulled apart have corrosion on the inside of the cases and the bases of the bullets.
The powder was actually stuck to the bullets and the inside of the case. I had to scrape the inside of the case with a pick to break it off, you can see a granule still stuck inside though.
Should I be worried about this? What would cause this? Would the powder be safe to use for fireforming? Are the cases safe to use?
The powder is Accurate 3100, which was discontinued several years ago. The 1lb can he gave me has a price sticker with $18 on it and it was stored in his garage (in ND) so it could have been through several hot/cold cycles but I believe all of the loaded rounds were stored indoors.