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.308 case bulging ............... ?

winxp_man

winxp_man

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Jun 20, 2009
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Sacto, CA
#1
Hey guys I noticed a slight bulging ring on my Winchester and Lapua brass. Not all of the bulge is even or that visible. My only idea can be that im running my loads to hot or something is not right with my Remington 700 SPS Tactical 20" chamber. This is all .308 stuff. I looked down inside with a flash light and even ran a needle down in the case to see if there is a case split but that does not seem to be the a problem. Now is this normal ? oh and some of the bulges are not even most of the lapua brass is only showing a half ring.

thanks for any help! I will try and post some pics asap.
 
#4
Re: .308 case bulging ............... ?

Have the cases been reloaded?

I have seen instances of improperly adjusted seating dies causing similar issues with brass, usually along the case shoulder, when seating a round and the seating die body is screwed too far into the head of the press. The unsupported shoulder of the case is driven into the shoulder of the seating die and since there is less room (at least with the RCBS die sets) between the shell holder and shoulder of the case, the shoulder bulges out. This is usually only found under close inspection or an attempt to chamber the round.
 
#5
Re: .308 case bulging ............... ?

Yes these are reloaded cases...... Here is a pic of them
59a16f8b.jpg
 
#7
Re: .308 case bulging ............... ?

Well I think that's were the Sizing die stops but what get me is the ring is not ways around the whole case just about half way around. Can it be the chamber is not really straight or the sizing die is not working like it should.
 
#8
Re: .308 case bulging ............... ?

In my previous post, the ridges was referring to were at the top of the case near the shoulder, not down by the case head like what you're having.

What kind of a load are you running? It looks like I'm seeing flowed primers on both cases, and it seems that the Lapua case has more primer flow and less case damage than the Winchester case that looks (in the photo) to have less primer flow. I'm seeing the beginnings of case head separation. How many firings on these cases?
 
#11
Re: .308 case bulging ............... ?

You have a slightly large chamber. The resized or new brass is pushed against one side of the chamber by the ejector. When it goes bang it is off center. The bulge is away from the side that contacts the chamber wall. I'd mark that bulging side with an ittsy-bittsy mark on the rim with a tiny slotting wheel in the dremel so that you can make it chamber the same place (9-o-clock is my bet) each time. You'll get more consistency that way. JMHO
 
#12
Re: .308 case bulging ............... ?

Well thanks for the info guys....... As for loading to hot the lapua was a little hotter because when I went from Winchester to the Lapua brass I thought that my Lapua will be ok with 44.5 of varget but the bolt was a little stick.
 
#14
Re: .308 case bulging ............... ?

I just threw the Lapua cases on my scale and most come out to 174 gr and Winchester come out at 155-160 gr. So that does explain the higher pressure.
 
#15
Re: .308 case bulging ............... ?

If your chamber's not reamed correctly, think about contacting Remingtob and send it back. This likely messes with your accuracy.
 
#17
Re: .308 case bulging ............... ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hink</div><div class="ubbcode-body">In my previous post, the ridges was referring to were at the top of the case near the shoulder, not down by the case head like what you're having.

What kind of a load are you running? It looks like I'm seeing flowed primers on both cases, and it seems that the Lapua case has more primer flow and less case damage than the Winchester case that looks (in the photo) to have less primer flow. I'm seeing the beginnings of case head separation. How many firings on these cases?</div></div>

I'm running was running 44.4 grains of IMR 4064 in both the Lapua and the Winchester, and I have shot the Lapua once and the Winchester twice.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">You have a slightly large chamber. The resized or new brass is pushed against one side of the chamber by the ejector. When it goes bang it is off center. The bulge is away from the side that contacts the chamber wall. I'd mark that bulging side with an ittsy-bittsy mark on the rim with a tiny slotting wheel in the dremel so that you can make it chamber the same place (9-o-clock is my bet) each time. You'll get more consistency that way. JMHO</div></div>

Dam I just fully read your statement now that I'm on my computer instead of my phone and this make really good logical sense. thanks for the info.
 
#18
Re: .308 case bulging ............... ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: winxp_man</div><div class="ubbcode-body">Well my only real big concern is that my brass will not last that long. </div></div>

It will last a long time if you don't work it back and forth a lot through firing/resizing.

I just neck size my cases, and it seems like they last forever.
 
#19
Re: .308 case bulging ............... ?

^^^ good point as a matter of fact a few weeks ago I just got a neck sizing die only. I also read from another hide member I believe that if you neck size after the first fire from it can improve your accuracy.
 
#20
Re: .308 case bulging ............... ?

+1 on the neck sizing. With that amount of expansion, neck sizing should prolong case life. It will also decrease the amount/number of times you need to trim. The chambers I've had that were like yours, when I full length resized to just bump the shoulder, the body of the case had to be sqeezed/sized as well and the case length grew. Sometimes I trimmed with each reload and other times it was every other reload. With neck sizing, you might go 4 or more without having to trim. Just keep an eye on it.
 
#21
Re: .308 case bulging ............... ?

First off, I'll be damned if that is normal in any way. I have had over 30 different 308's, from custom tight necked 'National Match' chambers to standard SAMMI spec factory stuff. I never had an issue such as that.

I have only seen that type of case deformation once and it was in a way FUBAR'd chamber. The smith owned up to a mistake during chambering, and replaced the barrel for my acquaintance at no charge. I would at least ask Remington for their input.

I can't see the bulge on the Win case, and on the Lapua the primer looks cratered to me, classic high pressure sign, so maybe that is part of the issue, but pressure alone ain't causing that.

If the rifle is shooting well, that's good, but I would be at a bare minimum getting a chamber cast ASAP. If you are just neck sizing and the bulge remains constant, then it would concern me less, but I would not be comfortable with that bulge ocurring at all.

Good luck on figuring it out--I'll be interested to know where you end up.
 
#22
Re: .308 case bulging ............... ?

well from what "former naval person" explained I took a look at what side the bulge seems to be happening and it seems just like he stated about the extractor pushing the case to one side of the chamber and when fired the bulge forms on the side of where the extractor pushes the case.

I will reload a few Lapua and some Winchester cases but this time only neck sizing and see what happens and post results.
 
#23
Re: .308 case bulging ............... ?

The chamber seems a bit sloppy and the firing pin hole could be on the large size also. Remingtons suffer from this problem.
I would try harder Remington primers .
The case expansion is normal for a sloppy factory chamber .
I have one 308 with a tight neck , tight base match chamber and I have to size down new brass to go in the chamber witha small base body die. That way the case starts out a neat fit and no bulge happens as the fit is less than the elastic limit of the brass. On my normal factory chambers I get the same base bulge as you on first firing. You could run a narrow strip of cello tape around the base of each new case before you fire it. This kind of centers it up to fire form with a more concentric bulge. After that it is not required again.
 
#24
Re: .308 case bulging ............... ?

OP's condition is exactly what I see on my Rem 700 SPS Tactical 20". Fish may see this as a problem but I have seen this on my other rifles for which I load. I don't think it's evidence of bad machining necessarily so much as a more likely challenge - probably some concentricity issues during resizing.
 
#25
Re: .308 case bulging ............... ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: boltstop</div><div class="ubbcode-body">OP's condition is exactly what I see on my Rem 700 SPS Tactical 20". Fish may see this as a problem but I have seen this on my other rifles for which I load. I don't think it's evidence of bad machining necessarily so much as a more likely challenge - probably some concentricity issues during resizing. </div></div>
I agree it is not a big issue . I think the harder Remington primer will fix the cratering of the softer primer.
It is a Tactical weapon , not a match rifle. Tactical rifles need to have chambers that will accept ammo without chambering issues and be able to use all brands so a tight match chamber is not the best thing for total ammo reliability .
 
#27
Re: .308 case bulging ............... ?

Well about the cratered primer the Lapua were a little hot.
I had IMR 4064 @ 44.5 which was a little hot even the bolt was a little sticky.
 
#28
Re: .308 case bulging ............... ?

Backing the load off a bit will help reduce cratering no matter what is causing it. Remingtons have a bit of an issue with oversize firing pin holes and using soft primers but any primer in any gun will crater if you push the pressure high enough.
You never mentioned a sticky bolt previously that I can remember .
 
#29
Re: .308 case bulging ............... ?

no I didn't it was very light but enough to say that its not normal. But as in the load I will go down to 44.0 and see what happens. In the Win brass due to the fact that its not as thick I had no problem at all.
 
#30
Re: .308 case bulging ............... ?

I would just back off a bit on the powder and use Remington primers as they are designed to be harder and resist cratering in a 700 action.
I use the 7 1/2 in my 223 all the time for max loads . If I substitute a softer primer I get cratered or even split primers now and then.
 
#31
Re: .308 case bulging ............... ?

There are 2 problems. The first is the Winchester brass. It is undersized to start with. Measure at the base on a virgin piece and you will see. Second, is a slightly oversized chamber.
 
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