Shearing off a hair ring of brass during crimp

[robg]

Looks like too much shamfer on the cases making the edge very thin ,over crimping as well, die shouldn't be near shell holder.

[ShooterAZ]

Just FYI, the pictures posted by Iron369 look nothing like the problem I or the OP are having. We are talking about a brass ring even thinner than a human hair...microscopic.

[jsizemore]

Even without any projectiles.

Sometimes the quality control at Lee is wanting. Got a seater/crimp die and it was like an armadillo inside. I sent it down the road for free so a fella could practice his machining skills. Never heard how it turned out.

[44Blam]

Crimp a little less and make sure to chamfer the inside/outside of the case...
One thing - those little 'hairs' if still attached can cut right through you skin and you'll bleed like a stuck pig... I had one do that many years ago when first started loading 44 mag and I saw the hair and pulled it - that little cut would not stop bleeding!

[greenjoytj]

Insufficient outside deburr of the case mouth, combined with excessive crimp.
There is no need whatever for that heavy a crimp, even in a tubular magazine rifle.
Back it off!

I was doing a very minimal de-burring, trying not to cut an actual chamfers on either side of the case mouth, trying to keep the brass near original thickness to retain strength and to reduce mouth splitting.
My Redding die makes a roll crimp and I was just crimping enough to get the case mouth to be flush with the edge of top drive band so the bullet if pushed back would be on the wide flat edge of the case mouth rather than a thinned out chamfered area.

I have a Redding Profile crimp die, used it in the past on Starline 45 Colt brass but didn’t like that it permanently embossed a ring about .018” wide all around the case mouth like a stair step.

So now I apply a classic roll crimp.

I have a LEE collet style crimp die haven’t used it yet because I’ve read it could push on the slope of the crimp groove and push the bullet deeper into the case.
I thought it might make it difficult to hit the cartridge recipe COL.

[mdi]

When troubleshooting a problem like this, closely inspect each round before and after each step, including cleaning and deburring. Often when looking for a problem's reasons, I will clean my brass deburr and closely visually inspect. Then after each proceeding step, again closely inspect. Visually if there is a problem like this thread, and I'll thoroughly measure the entire round when there is a fit problem. Finding out when the problem occurs, or presents itself is essential to fixing the problem..

[megasupermagnum]

I have not been able to measure any bullet movement while crimping with the Lee collet crimp die. The same cannot be said for the standard roll crimp, which often seats the bullet deeper if it wasn't seated initially just right for the crimp groove. Small variations in brass length effect the crimp quality, and cartridge OAL with a standard roll crimp. The collet crimp die is not effected by this in the slightest.

[mto7464]

why do any of you deburr pistol brass? I have never seen the need. Plus is that some of the brass that has that little sleeve inside?

[44Blam]

Usually one rotation of the inside and outside debur tool is enough to debur a case. More than that will thin the brass...

I resize/debur 44 mag but no other pistol brass...

[David2011]

why do any of you deburr pistol brass? I have never seen the need. Plus is that some of the brass that has that little sleeve inside?

Umm, to prevent this problem. I agree that the crimp is too firm but cannot agree with the suggestions to just iron out the flare. In a revolver or rifle the crimp is necessary to prevent boolit setback or extraction under recoil as well as to promote consistent ignition.

[greenjoytj]

mto7464:
Every pice of my revolver brass come with a burr inside the case mouth. Caused by the factory tube cutter when its cut to near correct length.
Factory outside edge is usually good but if the case requires trimming to length, then both sides will need de-burring.
Also if the cases are wet tumbler cleaned with SS pins there is nothing to cushion the brass from clunking rims against case mouths, so the case mouth can acquire some small dings that require smoothing out.

[mto7464]

mto7464:
Every pice of my revolver brass come with a burr inside the case mouth. Caused by the factory tube cutter when its cut to near correct length.
Factory outside edge is usually good but if the case requires trimming to length, then both sides will need de-burring.
Also if the cases are wet tumbler cleaned with SS pins there is nothing to cushion the brass from clunking rims against case mouths, so the case mouth can acquire some small dings that require smoothing out.

OK I assume for new brass but I load 9mm and use used brass and never have seen a burr nor need to trim.

[Moleman-]

I'd had that happen with new die sets for a short while until they get used a bit.

[Bazoo]

why do any of you deburr pistol brass? I have never seen the need. Plus is that some of the brass that has that little sleeve inside?

Why do I deburr my pistol brass? Well, because if its revolver brass I trim it for consistency.

I havent trimmed auto pistol brass up till now, but im going to try a batch and see how it does.