Deformed Cases

KAM_Indianapolis · June 9, 1999, 05:35 PM

Just started using my new reloader yesterday. This is also the first time I've ever reloaded.

The cases seem to be getting crimped real bad on one side. Happened to about 5 bullets out of 30. It looks like the case collapsed on one side. Didn't change anything between the good and bad ammo.

These are once fired Win 9mm Brass. De-primed and sized. Then cleaned with a corncob medium. After that I made sure there was no corncob left in. Primed them, flared and filled with powder (4.6g Bullseye), then pressed the bullet in (115g FMJ).

Don't know if I'm doing something wrong, or have something setup wrong.

Any help would be appreciated.

Thanks...
Keith

Art Eatman · June 9, 1999, 08:42 PM

When you set your de-capping/expander die for depth, did you adjust it to provide a very slight "bell" of the case mouth?

It should be belled just enough such that the bullet will barely fit inside the case mouth.

Then, as you seat the bullet, the seating die should be set up such that the crimp or taper-crimp part of the die swages the bell back down to the proper diameter.

Grayfox · June 9, 1999, 08:53 PM

Several posabilities just off the top of my head.

Not enough flare on the case mouth. The bullet could be hanging on the edge.

Crimp die is adjusted too tight.

Cases are too long. This isn't very likely with the 9mm as they seldom need trimming. But should be checked anyway.

You didn't say if all the cases are the same brand. Some are a little thicker than others and may not crimp properly if the reloader is set up for another brand. Check to see if one brand is giving you problems. If so, load them seperately after reseting the dies.

**Mal H** · June 9, 1999, 09:19 PM

Some more possibilities:

Are you trying to seat the bullet too deep? If so, the crimp ring may be trying to crimp while the bullet is still going in. What is the OAL you are going for?

Are the bullets set on the casings straight up and down before starting to seat? If they are canted too far, the seating die won't be able to straighten it out before damaging the casing.

Cheapo · June 11, 1999, 11:25 AM

Or perhaps an even simpler cause, if I understand the problem correctly (pictures scanned into the old 'puter would help a lot).

Is the bullet tipping over as you run the ram up? I like to use the minimum mouth belling possible, which means that sometimes a short case doesn't get quite enough and it loses its grip on the bullet base before seating begins.

So, I often guide the case/bullet up into the die. Once in there, the bullet can't tip over and catch the case mouth. With my dies at least.

KAM_Indianapolis · June 12, 1999, 08:25 PM

Thanks for the help. I've been a bit busy but will be trying your suggestions tomorrow (Sunday). If that doesn't help I'll scan some pics in to help with the diagnoses.

Peace...
Keith

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June 9, 1999, 05:35 PM	#1
KAM_Indianapolis Senior Member Join Date: February 3, 1999 Location: Indianapolis, IN, USA Posts: 612	Just started using my new reloader yesterday. This is also the first time I've ever reloaded. The cases seem to be getting crimped real bad on one side. Happened to about 5 bullets out of 30. It looks like the case collapsed on one side. Didn't change anything between the good and bad ammo. These are once fired Win 9mm Brass. De-primed and sized. Then cleaned with a corncob medium. After that I made sure there was no corncob left in. Primed them, flared and filled with powder (4.6g Bullseye), then pressed the bullet in (115g FMJ). Don't know if I'm doing something wrong, or have something setup wrong. Any help would be appreciated. Thanks... Keith

June 9, 1999, 08:42 PM	#2
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	When you set your de-capping/expander die for depth, did you adjust it to provide a very slight "bell" of the case mouth? It should be belled just enough such that the bullet will barely fit inside the case mouth. Then, as you seat the bullet, the seating die should be set up such that the crimp or taper-crimp part of the die swages the bell back down to the proper diameter.

June 9, 1999, 08:53 PM	#3
Grayfox Senior Member Join Date: December 17, 1998 Posts: 1,885	Several posabilities just off the top of my head. Not enough flare on the case mouth. The bullet could be hanging on the edge. Crimp die is adjusted too tight. Cases are too long. This isn't very likely with the 9mm as they seldom need trimming. But should be checked anyway. You didn't say if all the cases are the same brand. Some are a little thicker than others and may not crimp properly if the reloader is set up for another brand. Check to see if one brand is giving you problems. If so, load them seperately after reseting the dies.

June 9, 1999, 09:19 PM	#4
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 16,947	Some more possibilities: Are you trying to seat the bullet too deep? If so, the crimp ring may be trying to crimp while the bullet is still going in. What is the OAL you are going for? Are the bullets set on the casings straight up and down before starting to seat? If they are canted too far, the seating die won't be able to straighten it out before damaging the casing.

June 11, 1999, 11:25 AM	#5
Cheapo Senior Member Join Date: November 19, 1998 Posts: 986	Or perhaps an even simpler cause, if I understand the problem correctly (pictures scanned into the old 'puter would help a lot). Is the bullet tipping over as you run the ram up? I like to use the minimum mouth belling possible, which means that sometimes a short case doesn't get quite enough and it loses its grip on the bullet base before seating begins. So, I often guide the case/bullet up into the die. Once in there, the bullet can't tip over and catch the case mouth. With my dies at least.

June 12, 1999, 08:25 PM	#6
KAM_Indianapolis Senior Member Join Date: February 3, 1999 Location: Indianapolis, IN, USA Posts: 612	Thanks for the help. I've been a bit busy but will be trying your suggestions tomorrow (Sunday). If that doesn't help I'll scan some pics in to help with the diagnoses. Peace... Keith