Lapua brass w/ split necks after 5 loadings

[TimK]

I bought Lapua .308 brass new. I'm running 44g of Varget behind 168g SMK's (moderate load), and I neck size to 0.337" and bump the shoulder every time. No expander ball ever.

They've all been fired 5 times now. I noticed two out of 100 that had neck splits after neck sizing for the 6th loading.

I've not annealed them.

Does this seem way too soon for neck splits? Am I doing something stupid and causing this problem myself?

Note, I was planning to try annealing this cycle, but ran out of time. I'll certainly anneal before I load again, but I thought I should expect roughly 10 loadings without annealing.

 

[desertHK]

Re: Lapua brass w/ split necks after 5 loadings

Do you FL each time? I load very hot for my 155 scenars at 48 Varget and I am up to somewhere between 18-20 x already without any signs of neck splitting. I have never anneal the neck, but I only neck size it.

 

[1shot2kill]

Re: Lapua brass w/ split necks after 5 loadings

what is the inside diameter of the necks after firing?

 

[ChrisGarrett]

Re: Lapua brass w/ split necks after 5 loadings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tim K</div><div class="ubbcode-body">I bought Lapua .308 brass new. I'm running 44g of Varget behind 168g SMK's (moderate load), and I neck size to 0.337" and bump the shoulder every time. No expander ball ever.

They've all been fired 5 times now. I noticed two out of 100 that had neck splits after neck sizing for the 6th loading.

I've not annealed them.

Does this seem way too soon for neck splits? Am I doing something stupid and causing this problem myself?

Note, I was planning to try annealing this cycle, but ran out of time. I'll certainly anneal before I load again, but I thought I should expect roughly 10 loadings without annealing. </div></div>

I had a Norma 338LM neck split after 2 cycles, the other 19 are on their 5th.

Shit happens.

Chris

 

[TimK]

Re: Lapua brass w/ split necks after 5 loadings

I called Lapua, and they think my chamber is big.

 

[CanPopper]

Re: Lapua brass w/ split necks after 5 loadings

Then you should anneal after every 2 loadings.

Big chamber plus work hardened necks can lead to split necks. Right now, I'm using a sonic cleaner to clean my brass so I anneal and dry the brass all in one step everytime. Haven't gotten a split neck since.

 

[ChrisGarrett]

Re: Lapua brass w/ split necks after 5 loadings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CanPopper</div><div class="ubbcode-body">Then you should anneal after every 2 loadings.

Big chamber plus work hardened necks can lead to split necks. Right now, I'm using a sonic cleaner to clean my brass so I anneal and dry the brass all in one step everytime. Haven't gotten a split neck since. </div></div>

Measure a fired case at the mouth and post it here.

Do it, do it now.

My Savage 10FP blows my necks out to about .343"-.344" and I don't think that I've had a neck split due to it being a bit on the sloppy side.

Chris

 

[Rafael]

Re: Lapua brass w/ split necks after 5 loadings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">
Measure a fired case at the mouth and post it here.

Do it, do it now.

My Savage 10FP blows my necks out to about .343"-.344" and I don't think that I've had a neck split due to it being a bit on the sloppy side.

Chris </div></div>

Same here. Same dimension in my Savage.....never split a Lapua neck and I never anneal. I have used them to 50 firings.
The only split necks I ever had in this weapon were from new PMC ammo.

 

[MitchAlsup]

Re: Lapua brass w/ split necks after 5 loadings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tim K</div><div class="ubbcode-body">I bought Lapua .308 brass new. I'm running 44g of Varget behind 168g SMK's (moderate load), and I neck size to 0.337" and bump the shoulder every time. </div></div>

Take a couple of fired cases and measure the diameter of the obturated neck. if this is more than 0.006 bigger than the 0.337 bushing, you need a bushing 1/2 way between the obturated neck size and the final neck size bushing.

Sizing the neck is two small steps creates less work hardening than sizing the neck in one big step. Mainly because when you size in one big step the neck ends up smaller than the size of the bushing by 0.0005 to 0.001.

Also, go slow on the lever when sizing the neck--don't just ram it home.

{I have almost 30 NO sizings of my WIN cases (batch of 100) without a sngle neck crack or failure.}

 

[TimK]

Re: Lapua brass w/ split necks after 5 loadings

A fired neck is 0.344". Current plan is to anneal and save my allowance for a new barrel.

I have some Federal brass with two cycles on it. I'm going to shoot it a bunch and see if it does any better. If it survives longer than the Lapua, I'll be calling them back...

 

[Rafael]

Re: Lapua brass w/ split necks after 5 loadings

What dies are you using?
Bushings? Are they standard or Titaium-Nitride coated?

I have been told that neck sizing in steps is good...but I still go from .343/.344 to .335 or .336 with a single bushing without problems. It works for me.

You dimensions are the same as Chris's and mine.
It's bad brass or a problem with your dies/bushings.
I would not replace the barrel because of this.

 

[TimK]

Re: Lapua brass w/ split necks after 5 loadings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body">What dies are you using?
Bushings? Are they standard or Titaium-Nitride coated?

I have been told that neck sizing in steps is good...but I still go from .343/.344 to .335 or .336 with a single bushing without problems. It works for me.

You dimensions are the same as Chris's and mine.
It's bad brass or a problem with your dies/bushings.
I would not replace the barrel because of this.

</div></div>

Redding bushing die, standard bushing. You guys are using Lapua brass?? If that's true, I'll be calling the Lapua guy again.

 

[ChrisGarrett]

Re: Lapua brass w/ split necks after 5 loadings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tim K</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body">What dies are you using?
Bushings? Are they standard or Titaium-Nitride coated?

I have been told that neck sizing in steps is good...but I still go from .343/.344 to .335 or .336 with a single bushing without problems. It works for me.

You dimensions are the same as Chris's and mine.
It's bad brass or a problem with your dies/bushings.
I would not replace the barrel because of this.

</div></div>

Redding bushing die, standard bushing. You guys are using Lapua brass?? If that's true, I'll be calling the Lapua guy again. </div></div>

I step down from .343"-.344" to a .340" bushing, or a .339", then I'll go to the .336" TiNi for Lapua brass, .335" for LC brass, .334" for Federal and some Winchester and even a .332" for other Winchester brass.

To be fair ot Lapua, you might be work hardining your brass by moving it that much in one step, but who knows for sure?

Splits happen. There's no guarantee on how many 'cycles' you can get on any brand of brass, so you're kind of out of luck on that front.

Buy a step down bushing for all of your bushing dies for brass fired from non-match sized chamber/throats. I'm surprised you're using a .337" bushing, but maybe the necks are a bit thicker now?

Chris

 

[TimK]

Re: Lapua brass w/ split necks after 5 loadings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">

Buy a step down bushing for all of your bushing dies for brass fired from non-match sized chamber/throats. I'm surprised you're using a .337" bushing, but maybe the necks are a bit thicker now?

Chris </div></div>

I'll try that. As for the .337" size, I got talked into that by someone who seemed to know what he was talking about, but .001" tension seems low to me. A .336" would be even worse as far as work hardening, but maybe not so bad if I go at it in steps.

 

[vman]

Re: Lapua brass w/ split necks after 5 loadings

Try annealing the necks as well, provided you do it right you wont be hurting the brass.

 

[former naval person]

Re: Lapua brass w/ split necks after 5 loadings

Agree with vman. Anneal and watch. The blank that the case was formed from could have an imperfection. I saw a presentation years ago where a tiny nick on the edge of a blank became a longitudinal fault up the case. The forming/blanking die could have developed a tiny-teeninesey fault (as we say in the South) that allowed a fault line up the case neck.