2nd Broken Lapua Case for .223

[GunnyUSMC]

This is the second Lapua case that separated about halfway between the shoulder and base. The first time it happened, I realized that i may have been oversizing the case so I took the time to reevaluate and adjust my process. Even with this adjustment, i had another case separate only this time, the neck remained in the chamber. Fortunately, I was able to remove the upper part of my brass from the chamber without issue.

Notes:

• This latest event was with a different lot of brass from the first experience
• I have 6 firings on this lot of Lapua Match brass
• I anneal after every firing. I now use the AMP annealer
• I do not overpressure my loads on the .223
• No pressure on the bolt when loading a round and no pressure on the bolt when ejecting the case

Any thoughts?

 

[SecondsCount]

The only time I have ever had issues with case separation in 223 was when I oversized. I had not realized that there was a hard buildup of lube in the die, and it was pushing the shoulder back .010" more than necessary.

 

[jwv2001]

I'll bet the case was separating on a line between where you annealed and the rest of the case. I think your annealing is weakening the case along that line.

 

[Coyotefurharvester]

Usually case separation occurs well below the midline. If it is a case separation from oversizing, other cases sized and fired the same way will already have the case wall stretched and thinner. There isn't a way to reverse it. If it is an annealing caused problem, stop annealing and work harden the brass by loading and shooting.

 

[ArtinNC]

I can't believe the posts of people having case problems . All this good stuff we now do must be the problem . I have loaded some of my cases 50 times and can't ever remember having a problem , with case separatetion

 

[Webster]

I'll bet the case was separating on a line between where you annealed and the rest of the case. I think your annealing is weakening the case along that line.

The temperatures on the case body are not high enough to do any annealing. Do you get all the lube of of the cases? I have almost 20 reloads on my 6BR cases. Got to be something else? Do you check with a bump gauge to make sure you are not setting the shoulder back to far? If you solve it I would like to know how you did it.

The search option may find guys that solved the problem. What ever it is the case is being stretched lengthwise. I would think this can only happen if there is an open space for it to stretch into???

 

[joshb]

It sounds like you’re pushing the shoulder back too far. Go over everything and triple check your measurements.

 

[T.Rhodes]

.... pictures would be useful.

 

[Kevin1990]

Watching this one.

 

[nakneker]

It sounds like you’re pushing the shoulder back too far. Go over everything and triple check your measurements.

I was thinking the same, how much shoulder bump are using?

 

[SeabeeKen]

Take a paper clip and bend about 1/8" 90 degrees and file a point on it or use a mechanic pick. Put it down in the cases and rub that point up and down the inside of the case feeling for a groove where the case is thinning. Use a bore scope if you have one to look in them. Toss the ones with the groove in them. I'd be taking some measurements on fired and sized cases also

 

[243winxb]

Photo from AMP Annealing. https://www.ampannealing.com/articles/42/annealing-under-the-microscope/
Donuts .002" +

 

[mgunderson]

Assuming bolt gun, but checking to be sure.

 

[whatsupdoc]

I have had this type of case separation where it stretches approximately half inch below the shoulder. It has only happened on 223 brass.

1) It has happened on multiple barrels so it is not the chamber.

2) I headspace to a new unfired case not a headspace gauge so my
headspace is tight.

3) I bump the shoulder back .001 and I check every second case to confirm.

4) I have used two different FL dies, a Redding S with bushings and a RCBS
that has had the neck honed and it has happened with both.

4) I anneal using a home made induction annealer and the annealing does
not reach the separation line.

5) I use a Giraud tri way trimmer (the cheap one) and thought that that may be thinning the brass where the case holder spins around the case but the edge of
the case holder and the stretch line do not match.



So let me know when you figure it out.

 

[shoot4fun]

First, admittedly, I push my 223 bolt gun pretty hard.
Secondly, I never bump the Lapua brassiere than.0015. That is NEVER!
I have had a few Lapua cases that separated mid way down the body eventhough I inspect the brass for potential use head separation every time.
The brass had six firings on it when the issue arose and an after action inspection of the brass showed no indictions, either a telltale shiny ring outside or a separation line felt inside.
The area of separation is, I believe, the weak point of the brass in this caliber. How have I felt with it?
I run the brass four to five times and retire it.

 

[divingin]

You figured out the "normal" separation (low on the body of the case), right?

The only times I've seen or heard of the neck failure (they appear much like 243 posted) were:

A) from someone's really old 308 cases. Probably fired a bunch of times without annealing, no idea on storage, but had been sitting for a couple/few decades. Necks tore off while sizing.

B) A buddy of mine took someone else's advice (as the guy was shooting pretty well) and turned his necks down to about .004". Those left the case necks in the rifle when firing.

FWIW, 243's 3rd picture does not look to me like incipient separation (though it may be.) Normally, I've seen a slightly wider exterior band that appears to be a sort of lighter colored matte band around the case body. I've never seen a very sharply defined line like the one shown. That looks more like where it rubs against the ammo box or something like that. But maybe that's just me.

 

[Evlshnngns]

What are your measurments on fired brass and what are your measurements when sized?

I own an embarrassing number of 223rem dies. They all do it different. One thing that is nice on some of the newer cartridges is tighter Saami tolerances (in every way).

 

[jwv2001]

Another thing I think is a contributing factor is all this talk of bumping the shoulder back. Do this and you are causing failure of the case. By "bumping" the shoulder, you are decreasing the headspace and causing the brass to stretch. When the cartridge is fired, it expands to fill the chamber. Keep doing this and the case will fail.
When you fire the cartridge, you have just performed the best resizing there can be, You've pressure formed the case to exactly fit your chamber. The headspace is perfect. All that's left to do is work the neck to accept the bullet.
Buy a neck sizer or a Lee Collet die and leave the case shoulder and body alone.

 

[qldreloader]

Another thing I think is a contributing factor is all this talk of bumping the shoulder back. Do this and you are causing failure of the case. By "bumping" the shoulder, you are decreasing the headspace and causing the brass to stretch. When the cartridge is fired, it expands to fill the chamber. Keep doing this and the case will fail.
When you fire the cartridge, you have just performed the best resizing there can be, You've pressure formed the case to exactly fit your chamber. The headspace is perfect. All that's left to do is work the neck to accept the bullet.
Buy a neck sizer or a Lee Collet die and leave the case shoulder and body alone.

That's good for a couple of shots but I've seen bolt lugs damaged from continual neck sizing. Using your bolt to resize brass (when it has expanded to the point there is no or negative headspace) is not a good idea. Lots of lube on bolt lugs you might get away with it but it isn't practical and no good for ammunition to be taken into the field for hunting.

I neck size new brass for the first couple of firings to fully expand it and then bump the shoulder about 0.001" each time after that.

 

[qldreloader]

I have had 4 partial case head separations in the past 6 months with ADI 223 brass. I've been using ADI brass for decades now and never had problems.

Turned out the problem is that the ADIbrass is so popular down here that everyone is using it and I must have picked up some fired cases that were not from my rifle. Easy to do in competition with rapid fire strings at night in grass. I bet some of those cases were fired out of the police Remington R4 AR15s and were already stretched.