FrankenMauser: No ... I was saying that there is a 0.0004 ridge ... my micrometer measurements gave me a base average of 0.3081" and a shank average of 0.3077" ... by the way, the Remington brass doesn't have any trouble holding onto the SMK, V-MAX, or A-MAX bullets I use that don't have the ridge.
MrAwesome22: That was OS's first comment as well. The neck diameter is a little larger as the brass on the Remington is a little thinner. But even the Remington brass is a minimum of 0.003" under caliber.
I would agree with your expectation that 0.0004" shouldn't matter, but it looks like brass doesn't spring back like steel does, so once you pass the larger diameter through it, a few tenths DOES make a difference ... at least in annealed brass. I did a lot of troubleshooting on these, including FL resizing WITHOUT the expander mandrel installed ... which would have given an extra couple of whole thousandths of an inch of initial neck tension. That didn't help at all. After seating the bullets, you could literally pull them out of the case with just your thumb and index finger.
Like I said, this is mostly a warning to those who might want to use these bullets ... so they don't waste as much time I did trying to figure out what I was doing wrong. Match your brass with your bullets ...
There very well may be an issue with the Remington brass being over-annealed, but it is what is commercially available, hence my warning. Also, from my experience, it works fine with uniformly sized projectiles like the Sierra and Hornady offerings.