Tried but failed to post this on the handloading forum. I have some old cartridges lined up on a shelf in my shop that have been there for quite a while. Today when cleaning (every 20 years or so) I noticed a rifle cartridge oozing green liquid from the neck/bullet junction, and it's also split the neck. Bubbling and all. Must be something going on with the powder or powder and primer interaction, but I've never seen anything like this. Green no doubt from the brass, but something is making pressure inside the case for sure. The round appears to be a 2506, handloaded from a military 3006 case. It's probably at least 30 years old, maybe a lot more. What do you think?