And I'm not talking about what you might hear on CB radio. I had recently to picked up some "previously fired" Federal 556 brass from someone who didn't care for Federal brass. I know the reasons people don't like Federal brass, but none of this brass had been decapped and the primers were still crimped so I didn't feel I could go too wrong. Maybe 10% of it looked like it had just come off the range, but most appeared to have been wet tumbled. I took it home, punched out the primers, removed the crimp, and lubed it up with some Hornady Unique to resize it. I use an after-market carbide expander assembly in my die, so I typically only lube inside the neck of every third case. I've used Unique for about 15,000 cases since I found out about it and my only problem with it has been learning not to use too much, but I got that resolved last summer. So, I put the first case in the shell holder and raise it into the sizer die and I start getting a loud staccato sound that I can only describe as a chatter. The last time I heard anything like it was when I was learning machine tools and someone was using a dull bit and no cutting fluid. I've never heard anything like it resizing brass cases. I quickly reversed course, added a little more lubricant to both the case body and the case mouth and finished resizing the case. I stopped, cleaned the die and inspected it to make sure something had not happened since the last time I had used it. Nothing seemed to be amiss. As I went through the rest of the cases, the chatter seemed to reappear at random; but only with the really clean cases. The ones that didn't look like they had been tumbled never chattered. Each time I got a chatter, I would add a little bit more lube and the chatter would go away. Has anyone else experienced anything like this? Is it possible that the brass was tumbled in something that made the lube less effective? Or was it just so clean that the normal lubricity from the dirt and tarnish was simply not there? Or something I haven't thought of?