Tell me if I’m on the right track here (split cases)

[Joec7651]

Here’s my dilemma. 7mm RM, 160gr Partition seated the 3.290” OAL. 65gr RL-23, and WLRM primers. All rounds fired split the case between the shoulder and neck. It was new never loaded win brass.

So here’s what I found and did. Measured the COAL with a Hornady gauge with that PT bullet. It touches the rifling at 3.230”.

So I pulled the primers and saved them from unfired rounds. Threw the split cases away. Anealed the neck and shoulder, sized, and reprimed them. Used the same powder charge, and this time I seated to a COAL of 3.200” which puts the bullet .030” off the lands instead of jammed into them by .060”. I’m hoping anealing and seating to the proper depth for the rifle will solve the problem. This rifle doesn’t do this with other loads that I actually checked what the OAL should be. Opinions???

 

[mjcmichigan]

First comment, loaded long into a jam is likely the culprit.
When loading into the chamber, bullet hits the lands and jams down on the neck and shoulder. Stressing the case. Then, because there is no jump, the case takes a lot of pressure compared to a bullet with jump.

I think you did the right things.

I have a couple short throated guns and I don’t like seating so deep to allow a little jump.

Do you know a normally trimmed case won’t be pinched? That could cause trouble too. Does the empty sized case get pinched in the free bore.

You didn’t mention a heavy bolt close or open. I’m assuming you had both given what you described.

The charge you used doesn’t sound crazy to me.


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[SJB358]

That definitely shouldn’t have split on the neck with a bullet in the lands. Unless you’re right everywhere, your charge doesn’t sound outta line at all.

What brand of cases?

 

[RL338]

The newer Winchester brass I have seen have small splits forming in the neck/shoulder when taken out of the bag. Their brass needs to be inspected carefully prior to loading.

 

[JD338]

I agree with the others that you want to have some jump. .020-.030" is usually pretty good for a PT.
I think the W-W brass is the root cause of the problem. They usually have decent brass but you may have gotten a brittle lot.

JD338

 

[PJGunner]

A few years back I ran into that with a batch of Remington brass. Cartridge was the .308 Win. Two Hundred rounds all the same lot number. I annealed the ones that hadn't split and they've been good to go ever since. Methinks your brass may have missed the final anneal during production.
Paul B.

 

[SJB358]

A few years back I ran into that with a batch of Remington brass. Cartridge was the .308 Win. Two Hundred rounds all the same lot number. I annealed the ones that hadn't split and they've been good to go ever since. Methinks your brass may have missed the final anneal during production.
Paul B.

I have to agree with that.

 

[ShadeTree]

Be interesting to see if the whole problem was annealing, and what you did fixes it. Seems like the logical issue to me.

Splitting brand new cases at the neck/shoulder junction would certainly be an unexpected surprise.

 

[SJB358]

New made WW brass has been real bad lately. I’m not surprised really. Used to be tough stuff that just needed to be straighter.

The last 10 years it’s been hit or miss.

 

[jimbires]

sounds like bad brass , or not being annealed to me . I'd try annealing , if that don't fix it junk it .

some brass just seems to be junk ,no matter what you do . I anneal every cycle . I got out a box of ammo , from a year ago . it has split necks from setting in the ammo box .this brass has been fired 2 or 3 times . I've never had this before . years ago I had brass on the second fire the neck was coming off .

 

[RL338]

I managed to find a picture of new Win. brass I sent them because of their quality.

Not best picture but you look at the ones on the right you can see creases in the neck/shoulder. When fired these will crack through , found out the hard once. The quality of their brass fell off of cliff when they went to the black/red bags.

 

[mjcmichigan]

Wow. Crazy bad quality ... not even seconds quality.


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[ShadeTree]

I managed to find a picture of new Win. brass I sent them because of their quality.

Not best picture but you look at the ones on the right you can see creases in the neck/shoulder. When fired these will crack through , found out the hard once. The quality of their brass fell off of cliff when they went to the black/red bags.

Yep! They got me on 1 black/red bag in 22-250. Never again. The inconsistencies in overall length, primer pockets, and even shoulder measurements was crazy. It was like I got the stuff swept off the floor from different dies in the last 10 yrs.

No problems with cracking. It actually wasn't bad brass once I spent all the time prepping them and fireforming them. But I do believe I annealed them before first firing, don't remember for sure.

I got 2 bags of the old Blue/White bags in 348 Winchester, and some in 7mm-08. No comparison, that's pretty good brass.

 

[Joec7651]

First comment, loaded long into a jam is likely the culprit.
When loading into the chamber, bullet hits the lands and jams down on the neck and shoulder. Stressing the case. Then, because there is no jump, the case takes a lot of pressure compared to a bullet with jump.

I think you did the right things.

I have a couple short throated guns and I don’t like seating so deep to allow a little jump.

Do you know a normally trimmed case won’t be pinched? That could cause trouble too. Does the empty sized case get pinched in the free bore.

You didn’t mention a heavy bolt close or open. I’m assuming you had both given what you described.

The charge you used doesn’t sound crazy to me.


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The cases didn’t get pinched in the chamber. There was also no sticky bolt lift or flattened primers. It may be bad brass but jamming the bullet .060” Into the rifling didn’t help. It’s not a heavy enough charge to cause it either. After anealing and reloading, if it still happens I’m pitching the brass.

 

[Joec7651]

First comment, loaded long into a jam is likely the culprit.
When loading into the chamber, bullet hits the lands and jams down on the neck and shoulder. Stressing the case. Then, because there is no jump, the case takes a lot of pressure compared to a bullet with jump.

I think you did the right things.

I have a couple short throated guns and I don’t like seating so deep to allow a little jump.

Do you know a normally trimmed case won’t be pinched? That could cause trouble too. Does the empty sized case get pinched in the free bore.

You didn’t mention a heavy bolt close or open. I’m assuming you had both given what you described.

The charge you used doesn’t sound crazy to me.


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The cases didn’t get pinched in the chamber. There was also no sticky bolt lift or flattened primers. It may be bad brass but jamming the bullet .060” Into the rifling didn’t help. It’s not a heavy enough charge to cause it either. After anealing and reloading, if it still happens I’m pitching the brass.

 

[Joec7651]

BTW, it was Winchester new brass. Never fired.

 

[mjcmichigan]

[emoji3]. I was waiting for you to confirm the brass make. Well played!


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[TXbaldhunter]

I think too many times people think you have to be jammed into the lands to get a rifle to shoot good.How about finding a seating depth off the lands that shoots great.Jamming into the lands can be OK if you are not at max,but if you are at max,jamming into the lands can cause you some big pressure issues.I hardly ever load anything closer than .025 and usually I can get a rifle to shoot well between there and .100 off the lands.This is an interesting article on this subject. https://www.hornady.com/team-hornady/ba ... ballistics

 

[RL338]

Joec7651 , Could you post some pictures of the cases?

 

[TXbaldhunter]

I managed to find a picture of new Win. brass I sent them because of their quality.

Not best picture but you look at the ones on the right you can see creases in the neck/shoulder. When fired these will crack through , found out the hard once. The quality of their brass fell off of cliff when they went to the black/red bags.

I had that happen with me with Remington brass in my 7STW.I annealed the brass and those issues went away.