Significant difference between headstamps?

[Oldgoat03]

I have been reloading for about a year. I got a new (to me) Dillon SDB and just loaded a couple hundred rounds of 9mm with Berry's 124gr plated FP and 4.2 gr W 231. I am loading to 1.067" COAL.

The issue:
I was checking COAL and spot testing by pressing some into bench to ensure they are properly seated I discovered to my alarm that there were several that I was able to push the bullet back into the case against the bench!

When looking for clues I noticed that the loads using cases with FC or Blazzer headstamp were the only ones that were loose. The WIN, RP and SB cases hold fine. Interestingly I recall I had to adjust seating depth between these same case types to ensure consistent COAL.

I checked some ammo that I had loaded a while back on my Lee 4 hole Classic Turret press and those same headstamps seem to be ok. These were all cycled through the Lee FCD.

Anyone else have this experience?

Is the seating die and crimp die that much different on the SDB than the Lee?

Or is my SDB just still not quite adjusted properly?

At this point I just pitched the offending headstamps into my brass recycle bin.

Your thoughts, experiences and advice are appreciated.

Bob


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[rcmodel]

Is the seating die and crimp die that much different on the SDB than the Lee?

Taper Crimp doesn't hold the bullet in the case.

Sizing the case below required size, and then expanding it back up to .002"+ below bullet diameter it is what provides required case neck tension.

All the crimp can or should do is straighten the case mouth bell back out straight.
And insure the case mouth measures +/- .376" when you get done.

That being the case, I would suspect the Dillon sizing die is not sizing the case down enough.

Or the Dillon expander is expanding it too much oversize.

rc

 

[Oldgoat03]

RCModel

Thanks for your reply. I have been paying attention to all thats said here and realize the crimp does nothing more than remove the bell if adjusted properly.

I had wondered about the sizing die. It doesn't have any adjustment but it does seem a bit beat up around the carbide ring.

What should a properly re-sized 9mm case measure prior to flare?

I will go measure some cases after resizing to see what they are.

Thanks again.

 

[ATLDave]

I just ran into this problem with some 10mm cartridges.

 

[rcmodel]

In my old Pacific Carbide dies:
I just sized a 9mm Win case and it measures .372" at the mouth.

After expanding and belling, it still measures .372" just below the bell, and .373" at the bell.

The expander plug measures .350".
So assuming SAAMI spec case wall thickness of .0125" per side = .025" total?
It is just touching the sized case mouth, not expanding it.

It leaves the I.D. at a nominal .350" depending on brass hardness / spring-back.
Or .005" smaller then a .355" 9mm Bullet.

rc

 

[1SOW]

The issue:
I was checking COAL and spot testing by pressing some into bench to ensure they are properly seated I discovered to my alarm that there were several that I was able to push the bullet back into the case against the bench!

When looking for clues I noticed that the loads using cases with FC or Blazzer headstamp were the only ones that were loose. The WIN, RP and SB cases hold fine. Interestingly I recall I had to adjust seating depth between these same case types to ensure consistent COAL.

Not only yes, but I could have written that same statement minus the S&B cases.
I reload on a LEE turret press. With the "ATK" cases: FC, Speer, CCI and one or two others, My seating depth adjustment has to change (lighter) as much as .005".

I sort by headstamp. If I accidentally get an ATK case in with the WIN cases, IT WILL be seated .005" or even more DEEPER than the WIN seats. The handle pull is very noticeably lighter when the bullet seats in a FC case. Without looking, I can tell you when I hit an ATK case.
I have posted this before and many are skeptical. On a progressive press, the handle pull feel is "averaged" over all the cases . In a turret press, it's actually a single stage pull where you feel each case.

If I JUST load ATK cases and adjust for them, the cartridges come out uniform. The neck tension on these hold, but less than the harder cases do with the same measured taper crimp..

The FC/ATK cases are softer than WIN, WCC, R&P & PPU.

 

[dickttx]

"The expander plug measures .350"."

Interesting. I cannot use Precision Delta jacketed bullets in my 38 Super Starline brass. They will all push into the case with only small pressure. Running them into a 9mm die about 3/8", and using the 9mm expander, they work OK. Using digital calipers I cannot tell any difference in the 9mm and 38 Super expander. I get approximately .355 on both. I have thought I would order a smaller expander from Lee, but would not have thought of .350.

RC, as usual, I am pretty slow, so I missed adding my appreciation for your posts, as the thread was already closed when I read it a few days ago. Although I can tell you are a youngster, you seem to have crammed a lot of practical knowledge into your head. You are one of only two who post on the various forums I check that I always pay attention to. Not that I always agree, but I always pay attention. Thanks

 

[918v]

A FC 9mm comes out from my Redding sizer at .374" at the case mouth. The interior measures .351" using the small jaws of my Starrett dial caliper. The Redding expander plug measures .354". I have no case tension problems.

Mike your bullets. They could be undersized.