A friend has been having without warning the crimp starter catching the hull rim and then shell collapses spilling shot. It happens infrequently. He has been a reloader for years and we both have never heard of this problem before. Appreciate suggestions of how to fix the problem.

Are you saying that the pre-crimper is colliding with the mouth of the hull?

I would check for debris stuck inside the pre-crimper, and potentially a bent ball pivot pin

You said "older 9000", how old? Old enough to be using the metal crimp starter?? Take it apart and clean/examine it for something that is not right. Up grade to the new spindex easily adjustable style.
Just in case make sure the carrier plate stops in the correct spot, just past the lock. But I think if this was the issue you would damage more then 1 hull.
Could a primer not be fully seated causing the hull not to sit square. Should have caused an issue in station 3 but who knows.
This could turn out to be a "watch it and pay attention fix"

Steve

Possible problem, hulls now days varry in height. Didn't mention what brand hull is causing this. Some hulls are much stiffer than others, and extra height??

Ya, but I don't think any minor height difference would change the shell/die alignment, causing a problem.

I am wondering if the release for the shell plate advance is being triggered before it should be. That is the only thing that makes sense.

Usually the only thing that causes is the hull leaving the collet "trips/catches" on the collet fingers.

Steve

Can we assume this is happening on the down stroke because of "shell collapse"?

Steve

There is a lot of conflicting info. How does the shell rim get caught on the crimp starter?

Think we have a nomenclature problem here?