Lapua Brass- split necks

[InTheWeeds]

I have some Lapua .308 brass that have 4 reloads in them. I loaded a lot of 20 and six of them split their necks the other day. I load them pretty hot, shooting 175 SMKs at about 2750fps. Im using RCBS FL dies. Am I overworking the brass with these dies? Is there anything I can do to prevent this in the future? Should I give the remaining 14 cases another go or toss them? When the others split, I had no issues with the bolt jamming or gun damage..

 

[prosise]

Re: Lapua Brass- split necks

Personally you have a couple options. I would use Redding type S bushing dies & remove the Expander. The set comes with the non expander button. I was told by Speedy Gonzales that you should not size twice. Sizing dies size in on the down & then you size out on the upstroke. He calls that "Bad JUJU".. I would say your running might hot with the 175's. If for some reason your chamber neck is a skosh oversized it might be overstressing the brass when it fires.
You might drop the charge and just see how they do. Lapua is mighty tough & the fact that you split six is a definite warning from the "Reloading gods" that its time to look into the issue. I have some lapua in 6br with over 23 reloads, necks are loose as all get out but I never have split one. All in all I think that backing down on the charge will solve your problem and you can stay with your original dies.. Let us know what you find & decide on please. Good info to hear..

prosise

 

[rocketron]

Re: Lapua Brass- split necks

i would say it's time to aneal them

Ron

 

[TimK]

Re: Lapua Brass- split necks

I had a similar problem with a factory Remington chamber. It was so big it was allowing the brass to expand too much thus causing me to have to over work it to resize. I started annealing and the splitting has stopped.

Measure the diameter of a fired neck. If it's more than about 0.003" larger that a loaded round, you've found your problem.

 

[shoot4fun]

Re: Lapua Brass- split necks

Sounds like maybe a chamber issue. I ran into it one time with a factory Remington barrel. They replaced the gun. It was splitting necks on brand new brass reloads and factory ammo.

 

[Shrike]

Re: Lapua Brass- split necks

I second the chamber issue theory. Although I do not load hot, my bullets travel about 2750fps but have never had the necks split on me despite FL sizing every time. I usually throw my brass away when I can't feel ANY resistance when I put the primer in. I also gauge how hard it was to punch the old primer out. I know this is extremely qualitative, but when I discover that charactaristic, it's usually my last load for those cases. I keep track of how many times they're reloaded, of course. This usually occurs around the 6th reload for me.

Do you have any cases that didn't split? You might measure the inside diameter of the neck and compare it with a friend's measurements who doesn't have this problem. This might be another rough way to see if your chamber is out of spec.

 

[InTheWeeds]

Re: Lapua Brass- split necks

I guess its time to have my gunsmith blueprint my action so we can find out. I have some 1x fired Lapua brass that I will compare to.
IIRC, Lapua brass is annealed from the factory..

 

[KHOOKS]

Re: Lapua Brass- split necks

Yes there annealed from the factory but after you fire them and reload them a few times they become work hardened. Annealing them again will bring back the workability of the brass.

 

[shoot4fun]

Re: Lapua Brass- split necks

I have Lapua 308 that has many firings w/o additional annealing and not a cracked one yet. Yes, at some point I will have it annealed again but I measure case neck spring back after sizing and am still GTG.
But all my 308 rifles have custom chambered barrels by some of the top smiths.
My load is 45 gr Varget with 175 SMK. It pushes at 2725 fps.

 

[desertHK]

Re: Lapua Brass- split necks

You may working the die too much. I have over 20 reloads on my 308 Lapua brass. No issue whatsoever. However, I only neck size it. Yes, I push them very hot. 48 grains of varget behind the 155 scenars. For the 175 SMK, I also push them around 2750 fps.

 

[shoot4fun]

Re: Lapua Brass- split necks

I did switch to a Forster bump die with bushing. It sizes the neck and the base only.
Measure a loaded round and then a fired round (not split) to see how much neck expansion you have. If your gun is a Remington and is accurate for you then just have a smith true the action, set the barrel back some and recut the chamber.

 

[InTheWeeds]

Re: Lapua Brass- split necks

So should I measure neck diameter and thickness before resizing and avoid neck sizing if possible? I really dont pay much attention to neck tension. Im already getting .3 MOA groups, so I figure the extra time, effort and tooling isnt really necessary..

 

[shoot4fun]

Re: Lapua Brass- split necks

Are you FL sizing every time? That really stresses the brass all over and should be avoided. The Forster bump die does neck size to a precise diameter. Usually you want a resized neck to measure about .002 or .003 smaller than a loaded round for proper tension.
I am saying neck size every time and FL size when necessary.
Buy some Cerasafe and make a chamber casting. Then check with a reputable smith and see what they say about your chamber. It is very easy to do and should ease a lot of your worry.

 

[Shrike]

Re: Lapua Brass- split necks

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DesertHK</div><div class="ubbcode-body">You may working the die too much. I have over 20 reloads on my 308 Lapua brass. No issue whatsoever. However, I only neck size it. Yes, I push them very hot. 48 grains of varget behind the 155 scenars. For the 175 SMK, I also push them around 2750 fps. </div></div>

Seems like you should be pushing those scenars faster than 2750, unless you have a short barrel. I'm impressed you get so many reloads out of your brass! Maybe I should consider neck sizing only. I'm getting about .3MOA out of my rifle now, so I'm very happy. With these results, I just haven't got around to purchasing the Forster die.

 

[vman]

Re: Lapua Brass- split necks

I would not worry about the comment regarding not FL sizing.

If you set up your FL dies properly it should not be a problem.

Once you have brass that has been fired enough to allow you to determine your chamber size (when the brass wont chamber easily), you know it has reached the specs of the chamber internals.

You measure the head to datum line using whatever tools you have, or simply purchase some. Sinclair, Hornady and RCBS make them.

Whatever that measurement is on your cases that have reached max length for head-to-datum, you simply want to bump back the shoulder 0.001 to 0.002 inches for a bolt gun. This will allow the rounds to chamber easily.

In order to bump back the shoulder that much you need to just fiddle around with your die. Measure a case, size it, measure again etc etc until you have your case 0.001 shorter after FL sizing.

If you do that and combine this with case neck annealing your brass should last a long time provided your not blowing out the primer pockets or nearing case head seperation.