9mm Blazer and FC brass -- poor neck tension and set-backs .

[Walkalong]

Neck tension holds the bullet in auto cases. If you use enough crimp to help hold the bullet, you have over crimped IMHO.

As already posted, the sizer is too big, or the expander is too big, or some of both.

 

[Striker Fired]

The fact that he said he tried a different expander kind of eliminates too small of an expander, doesn't it? The fact that other brands of brass work fine eliminates most other "faulty" equipement or procedures, doesn't it?

To me it's thin brass or just brass that is too soft to hold the bullets he's using.

A smaller sizer will help for these pieces of brass but may need to be under the "standard" size that most mfgs make thier dies.

Those are the types of brass that I would use for oversize lead bullets.

 

[1SOW]

Maybe we are all discussing the wrong issue.

If a 9mm cartridge has a properly closed case-mouth and the typical "coke-bottle" shape, it has almost all the neck tension it has to offer.

If you stand a 9mm similarly loaded FC/Blazer cartridge and a Win cartridge on their bullet nose,
and add measured weight to the base until the bullet moves; I would BET that the Blazer/FC would move first due to having softer brass.

Maybe the amount of force the OP is applying is the issue.
How much is it "supposed" to hold anyway????

 

[PO2Hammer]

That's why I don't like the finger test.
It's so simple. Make up a few rounds without primers or powder. Measure their length. Load them into a mag and cycle them into the gun by sling shotting the slide, repeat twice.
Measure their length and note the set back.
Any set back .005" or less for three cycles is not an issue.

 

[Walkalong]

The fact that he said he tried a different expander kind of eliminates too small of an expander, doesn't it?

Probably. No guarantee, but yes, most likely.

Blazer brass isn't too thin.

Another thing to consider is that the 9MM is a tapered case. If the sizer is not adjusted down far enough, it will not size the case mouth enough. One doesn't have to worry about that with .40 or .45 etc.

 

[1SOW]

Any set back .005" or less for three cycles is not an issue.

Tried your test with just a few 9mm with WIN cases with 125JHPs. Zero setback in a CZ.

Win is my preferred/favorite brass, so I don't have any FC or Blazer loaded up. I sort by headstamp.
I do have some Remington/ R&P commercial 115JHP SD rds, and they didn't set back either.

ONE reason I sort by headstamp: In my turret press, if I load 50 rds of WIN headstamp and "1" FC/ATK brass case was mixed in, the ATK case will seat .004-.005 DEEPER into the case with the set-up and pull I'm using for the WIN cases. If I load ALL FC/Blazer/Speer, no problem with seating consistently.

I've tried to measure case wall thickness with my caliper, and they appear to be very close to the same as WIN. The 9mm "ATK" cases are simply "softer". When I sort headstamps I put FC, Blazer, Speer and *-* in the same containers. They all have the same "softer" reloading consistency for me. WIN, PPU and R&P all have the same characteristics of being "harder brass" in my press.


Back to the OP: something is wrong with the sizing.

 

[PO2Hammer]

Tried your test with just a few 9mm with WIN cases with 125JHPs. Zero setback in a CZ.

Nice. My CZ is easy on them too. It was while loading for a .38 Super 1911 that I first ran into serious set back issues. The feed ramp (feed wall?) is quite steep. I was experimenting with less and less expansion/flare to prevent the set back. I found a setting that worked, zero. Zero expansion/flare before bullet seating prevented set back like nothing else. Plus an added bonus was that they needed no crimp.

This is great for the turret and single stage guys, but I don't imagine it's too practical for youz progressive types. You sometimes have to hold the bullet as it enters the seater die and it works best with competition type seater dies. Plus it doesn't work for lead bullets. You'll scrape about 25% even with bevel bases. Plated bullets give about 99% reliability with the 1% getting 'skinned'. That can be prevented for lead and plated with a touch of the Lee universal expander tool. It's a cone shape flaring tool in a die. I only flare about .003", just enough to iron out any case mouth dings that cause the soft bullets to get scraped. The minimal flare disappears when the bullet is seated, so again, no crimping needed.

I see you have also run into the Win - FC OAL phenomenon. I sort too and that was a head scratcher.