Vertical Split case (body) fireforming

[Phys86]

Not sure yet. I've got the covid flu and am out commission for a bit. I'll resume investigating once I recover.

I did hear back from the Lapua distributor in NA though. They requested pictures and lot numbers. I gave them the full explanation of load, etc. We'll see what they say.

 

[Webster]

I fireformed 14 cases today, and had two of them split vertically in the body. I've never had this happen.

Lapua 284win virgin necked up to 30 cal, fireformed to Ackley improved. They chamber with a slight resistance.
55.0gr imr 4451
175 smk 0.020 off lands
Cci200

FF velocity average 2690 from 24" bbl. Velocity of the two that split was in line with the others.

This load is well within Max in Sierra's load manual for 30-06. My FF brass as a water capacity of about 70 grains.

Could this be caused by a defect in the brass? This load is definitely not high pressureView attachment 1517622View attachment 1517624

View attachment 1517626

What causes the equaly spaces lines on the case left and right of the crack. They don't appear or are very difficult to see above or below the crack. Probably nothig to do with the crack. It's just the copper oxide film being rubbed off? Is your chamber machined that rough?

 

[Phys86]

What causes the equaly spaces lines on the case left and right of the crack. They don't appear or are very difficult to see above or below the crack. Probably nothig to do with the crack. It's just the copper oxide film being rubbed off? Is your chamber machined that rough?

View attachment 1518543

Yes I think that might be from the chamber but only seems to be on the oxide layer of the brass

 

[Phys86]

I heard back from tech support at the Lapua NA distributor, Capstone Precision Group. He received my two split cases, cut them open and took some measurements. He said he found very little variation in case wall thickness and there appeared to be nothing wrong with them. He said he spoke with another guy there that does a lot of wildcat case forming and he stated that it just happens sometimes and there will always be an amount of waste that happens when fireforming wildcats.

That to me is a very unsatisfying response. I unfortunately didn't (and still don't) have any qualified reasoning or rebuttal to him for explaining this shouldn't happen with quality brass and especially not 2 cases out of 50 if it is just a "chance" occurrence.

 

[rwj]

I unfortunately didn't (and still don't) have any qualified reasoning or rebuttal to him for explaining this shouldn't happen with quality brass and especially not 2 cases out of 50 if it is just a "chance" occurrence.

You’re not using the case in its intended/design purpose. I can’t imagine any manufacturer providing reasons for what happened under such conditions. What explanation(s) were you hoping to receive?

 

[Phys86]

You’re not using the case in its intended/design purpose. I can’t imagine any manufacturer providing reasons for what happened under such conditions. What explanation(s) were you hoping to receive?

Yes I agree and wouldn't expect them to replace my box of brass or anything like that. I had just hoped to get further information on the cause other than "it happens". Many many people fireform wildcats with their brass, moving much more brass than I do with this chamber, yet there's very few cases I can find on the web of this happening with Lapua brass and it's odd to me that I had two cases out of 50 rupture. I would think that they would also want to know a more in depth answer, unless they truly just do not care because the chamber is not the intended purpose.

 

[Tesoro]

You also have head separation going on. Dont blame the brass yet!
Take the next 2 out of the box and slice them in half. And do same with brass that passed the test.

 

[Phys86]

You also have head separation going on. Dont blame the brass yet!
Take the next 2 out of the box and slice them in half. And do same with brass that passed the test.

Head separation? I have not experienced that. What do you see that suggests that?

 

[Tesoro]

Head separation? I have not experienced that. What do you see that suggests that?

 

[Phys86]

View attachment 1520969

I see. That is only the residual carbon staining the case. I rubbed it off with a finger and that was left over. Head separation should not be possible here, since these chambered with an interference fit at the neck/shoulder junction per Ackley's FF method

 

[rwj]

Yes I agree and wouldn't expect them to replace my box of brass or anything like that. I had just hoped to get further information on the cause other than "it happens". Many many people fireform wildcats with their brass, moving much more brass than I do with this chamber, yet there's very few cases I can find on the web of this happening with Lapua brass and it's odd to me that I had two cases out of 50 rupture. I would think that they would also want to know a more in depth answer, unless they truly just do not care because the chamber is not the intended purpose.

That would have been a reasonable expectation long ago. But in today’s litigious environment, that is very unlikely to occur!

 

[Old Navy]

I just had a friend send me this photo of some 30-06 Nosler brass he was fire forming to 6.5X57 AI. He was told no warranty for fireformed brass.

 

[Evlshnngns]

I just had a friend send me this photo of some 30-06 Nosler brass he was fire forming to 6.5X57 AI. He was told no warranty for fireformed brass.

That looks like fat a chamber. He should pull the barrel and measure it throughly.

 

[Old Navy]

That looks like fat a chamber. He should pull the barrel and measure it throughly.

Two year old problem. Different brand off brass cured the problem.

 

[Phys86]

I haven't fired formed anymore yet, but I have fired the already fired formed cases a couple more times, and haven't had any issues with those