Air dents as opposed to lube dents

[F. Guffey]

Is your die one where the expander is up high and is in contact with the inside of the neck when the case mouth starts to resize?

The step sequence is something that is most difficult for most to keep up with; but if that happens I would expect to see a case neck folded back thought the case shoulder; or a case with a missing neck after the ram was lowered.

There was an attempt to reduce the ‘clunk; time when lowering the ram. The sizing ball/expander was located high on the primer punch/expander ball assemble. Then there were those reloaders that punched the primer first then raised the neck sizing ball to reduce the travel distance.

If I thought the die was being sealed at the top I would use a die friendly rubber tipped air nozzle to pressurize the die and then stick the top of die into a bucket of water; and then check for leaks.

F. Guffey

[condor bravo]

Roger on that; complete agreement.

[Unclenick]

What I had in mind was some expanders are set closer to the top of the die body than the traditional type down at the deapping pin chuck. The idea is that when you then withdraw the resized case, the fact a little of the case neck is still inside the neck portion of the die when it starts to engage the expander will make that withdrawal start straighter, thereby mitigating the expander pulling the neck off-axis.

It simply occurred to me that if that were happening, it forms another air escape path blockage. Should that happen? No. Air should be escaping past the threads that the decapper is held in place by. These aren't class 3A threads, after all, so there should be plenty of gap in the thread helix for air to bleed past. But it's possible that if the press is operated fast enough, and especially if there is oil or grease present in the thread, that the air still won't be able to squirt out past the threads fast enough to avoid making a little added pressure. Not enough to dent the case, but enough to raise the amount of air trapped in the space I illustrated.

[condor bravo]

Yes I was aware of what you were getting at, should the expander be high up on the rod. Have never seen one like that but I guess they exist.

[Unclenick]

Yes. The Lee EZ-X expanders are like that and can be adjusted up in that neck fitting range. I've had better luck either mandrel expanding after sizing or using a carbide expander plus dry lube to minimize neck drag.