Split case

[AJ Peacock]

I'm certainly NOT any kind of machinist (as far as you can imagine from it), but could a FL die be 'adjusted' by polishing etc? to match you chamber better.

AJ

 

[birddog 68]

This may only be a bad batch of brass as other posters have alluded to. Get some new brass, maybe a different brand and see how things go before spending money that may not need to be spent. JMO

I think a combination of over working to get it sized and being a only mediocre brass are the problem. I do have brand new brass but it's Nosler also.

I'm certainly NOT any kind of machinist (as far as you can imagine from it), but could a FL die be 'adjusted' by polishing etc? to match you chamber better.

AJ

I am a half *** machinist and I did polish the die using Flitz but it didn't actually remove any material, only polished.
I'm not sure how they cut custom dies but it's possible that they harden after they cut to size?
I'd probably need to remove .004 to see a improvement.

 

[Mikecr]

Any options that I have overlooked?

A gun builder can replace your barrel with a better chamber.
For a Browning (barrels VERY difficult to remove) I think I used Kolbe, Easton, PA. Did a perfect job.

 

[cape cove]

Do you have a bore scope. If yes, then maybe you could scope your cases and see if there is anything going on inside. Just a thought.

 

[whatsahoya]

OP, weird question, but have you ruled out a chemical cause? Any chance this brass has been hit with anything containing ammonia? Several brass cleaners contain ammonia, which can have nasty effects on brass with residual stress. Your crack being below where you likely anneal got me thinking about season cracking.

 

[whatsahoya]

(This is me avoiding asking "did you let your cat pee on your ammo")

 

[birddog 68]

(This is me avoiding asking "did you let your cat pee on your ammo")

Although we do have 2 cats, the brass was never stored where they could pee on it. And before anyone asks, no I didn't pee on my brass!

 

[birddog 68]

Do you have a bore scope. If yes, then maybe you could scope your cases and see if there is anything going on inside. Just a thought.

Great idea. Thanks

 

[FEENIX]

The split is probably a defect created during manufacturing. Brass starts as a flat disk. That flat piece of metal could be thinner in a spot or the metal mixture may not be correct in that spot. The disk is then bent into a cup, the cup is then heated and stretched several times to elongate to the length of the cartridge, then .... So, maybe it's just a manufacturing defect of the one piece. They reject brass during manufacturing when a defect is detected. Maybe this one got by the inspection because it wasn't visible. I'd keep using the brass, but keep an eye on it like you normally do. If many start failing, then trash the lot.

Agreed! And often, end-users do not see it until x number of firings, though sometimes earlier. Below is my only split-brass incident. It is a virgin .338 NM by Lapua. Yes, that is correct, it is Lapua brass, and it happened when I was using my hydraulic forming die, from .338 NM to .338 Thor. This is the only one out of 105. And no, I didn't complain to Lapua.

But it is no sweat, I re-purposed it into a useful tool. LL!

 

[ButterBean]

The full length die will over work your brass, causing the case to split. Just my experience

Wrong

 

[ButterBean]

This is a first for me. I've had split neck's before but never on the body.
I worked up to pressure and then backed off a full grain which is how I normally do it. Next outing on the third shot this happened. Everything looks fine on the other cases, no pressure signs.
I'm thinking that there was some type of inclusion or the wall has just thinned too much from full length sizing but I'd like to hear what others think.
280 AI, Nosler brass on 5th firing. Was annealed after 3rd firing and primer pockets are still tight. 60 grains of IMR 4350 (.5 grain under book max) using 120 grain ballistic tip.View attachment 744591

That's a bad batch of brass

 

[FEENIX]

I am a half *** machinist and I did polish the die using Flitz but it didn't actually remove any material, only polished.
I'm not sure how they cut custom dies but it's possible that they harden after they cut to size?
I'd probably need to remove .004 to see a improvement.

Yes, Sir, you are correct! In my last full custom build, I ordered a corresponding sizing reamer. My GS built me a set of custom dies, including hydraulic forming, and a COAL gauge, using a blank die (not hardened), and he sent it to be hardened.

 

[birddog 68]

That's a bad batch of brass

Yes, I have decided to retire the whole batch. I got my use out of them and have plenty of new and once and twice fired brass.
No reason to risk safety over a $1.50 piece of brass

 

[Deputy819]

Here's a fine example of a "drawing process defect" that @MagnumManiac was referring to. This is a piece of ONCE fired ADG .300 Win Mag brass. I didn't notice any defects in the brass prior to loading, but I sure caught it after the first firing. The other 99 pieces were just fine. I contacted ADG ONLY to ask what it was. They expressed sincere regret over the defect and sent me a new piece of brass and a hat, too.