Ok, we've all got one. The ammo when you run out and see it's time to start production your heart sinks and you can only think "oh s**t, that time already?"
Mine is 7.62x39
Took me a while to develop out a good load, but still to this day this is my nemesis as there's always a problem when I start a run of this. Weather it's powder spills, missed primers, case neck breaks, or press problems in general. When I start this one, I know it's a night of swearing and frustration.
Might be the Russian connection?
What's yours? What's your horror story?