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Advice on a problem

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Category: Firearms, Bows, and Ammunition
Forum Name: Reloading & Ballistics
Forum Description: Anything to do with ammunition
URL: http://www.opticstalk.com/forum_posts.asp?TID=26726
Printed Date: March/29/2024 at 02:21
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Topic: Advice on a problem
Posted By: powderburn
Subject: Advice on a problem
Date Posted: December/26/2010 at 12:06
For the 1st time in 35 years have a reloading problem I can't figure out. Bought a stevens 308 bolt gun and this thing flattens primers no matter what I try. Factory loads , reloads with different brands of cases, primer, powder , bullets it doesn't seem to matter and I don't even load hot. As a matter of fact I am using the starting loads recommended to maybe 5% under max powder chg.. I have had the head space checked twice once by the factory. I have neck sized to just barely bumping the shoulder . I show no case head expansion or other pressure signs just flat primers. The odd thing is my buddy has a similar rifle in 7mm-08 and is experiencing the same thing. Maybe it just the nature of the beasts but it bugs me why and how. I have never seen this in any other rifle I've ever owned. Any one else experience this? Thanks for the advice.



Replies:
Posted By: 300S&W
Date Posted: December/26/2010 at 12:16
  If you have access to a chronograph you could see by your velocities if your having pressure problems.  Ex. - Is your starting load velocity alot higher than the book says you should be getting. Or is the velocity of the factory ammo your using alot higher than their specs call for.

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"I ain't got time to bleed!"


Posted By: powderburn
Date Posted: December/26/2010 at 13:23
No I seem to be getting expected velocities in the 2500-2700 fps range with 150 gr bullets. Like I say I don't load hot. That's what is so weird everything is pretty normal except the flat primers. No marks on the case head from the extractor, not hard bolt lift, case life normal, etc. I did buy some mil spec primers the other day to try that. I have scrubbed the bore to make sure there wasn't a carbon buildup or fouling of any kind. Cases are sized to where you can feel just the slightest resistance when closing the bolt. Thanks


Posted By: Dale Clifford
Date Posted: December/26/2010 at 13:28
my vote goes for really rough chamber. upon ignition the chamber is grabbing the case a little sooner than normal, while the primer backs out, as the chamber pressure increases and the bolt force increases beyond the release point, its pressed back against the primer reseating it. same dymanics as in revolvers.

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I love little league baseball-- it keeps the kids out of the house
Yogi Bera



Posted By: jonoMT
Date Posted: December/26/2010 at 14:20
Dale's probably right. I don't know if cleaning the chamber really well will help, but it won't hurt. Otherwise, sounds like it would need some professional attention.

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Reaction time is a factor...


Posted By: powderburn
Date Posted: December/27/2010 at 06:08
Dale I sort of thought it may be that too but I have the dies set to where if you take a resized case and just start a spent primer in the pocket and then chamber it the primer comes out seated flush in the primer pocket. So I'm not sure there is all that much movement in the case being shoved forward in the chamber so the primer can back out. If I understand your comment you are basically describing a head space issue accented by a rough chamber. As I said I was convinced that was the problem too but I've had that checked 2x, once by sending back to the factory and they indicated it was fine. The other was a local smith using go , no go gages. The weird thing is that my buddies rifle is exhibiting the same tendency. Thanks for the ideas .


Posted By: 300S&W
Date Posted: December/27/2010 at 06:21
 
   A bolt face problem?  


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"I ain't got time to bleed!"


Posted By: Dale Clifford
Date Posted: December/27/2010 at 09:09
Really doesn't take much to see this problem. Not anywhere near the thickness of the primer. This problem is seen frequently in ar 223, especially with suppressors, and is somewhat powder dependent. 

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I love little league baseball-- it keeps the kids out of the house
Yogi Bera



Posted By: powderburn
Date Posted: December/29/2010 at 10:55
300S&W I am beginnig to think this may be the situation as I have read that some savages exhibit a concave bolt face. Maybe it's just the nature of the brute and it really doesn't seem to hurt anything other than my sensibilities. Like I said I sent it back to savage with a letter explaining my concerns and a couple of cases exhibiting the problem. I got the rife back with 3 spent cases and a job ticket that said "checked OK and test fired" The problem was the 3 cases they sent back were flattened too so obviously they seemed to think it was normal. I was a bit disappointed in their reply and follow up to be truthful. I like the little rifle and other than this it's fine and maybe I just need to learn to ignore it. while I am really just wanting to find a nice 150gr load in the 2600fps range to settle on it sort of bugs me that I will never be fully comfortable loading it up to it's full potential if I should feel the need.


Posted By: cvedrick
Date Posted: December/29/2010 at 12:22
If the primer is flattened, but you do not see a raised ridge around the firing pin strike dimple, you are probably OK.

I had this happen to me with a well made custom using medium loads and freaked out a bit.  After looking at the spent casings from some of my mil-surp and factory rifles I realized it was more or less a normal thing even with crimped ammunition.  If that is the only indicator you have, don't worry about it.


Posted By: RifleDude
Date Posted: December/29/2010 at 12:30
I agree, regardless of what's causing this, if your velocities are inline with where they should be and you aren't getting any other pressure signs -- hard bolt lift, difficult extraction, primer pocket expansion, etc. -- I wouldn't worry about it.

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Ted


Money can't buy happiness... but it's much more comfortable to cry in a Porsche than on a bicycle.


Posted By: jonoMT
Date Posted: December/30/2010 at 10:50
I run a pretty stiff load through my .308s and have never had any extraction problems or any other sign of over pressure...except primers get close to flattening out. One thing I really try to do is keep the chamber clean. Leave a .45 bore mop in there overnight soaked something like M-Pro 7 and might be amazed what sticks to it.

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Reaction time is a factor...


Posted By: GaCop
Date Posted: January/03/2011 at 07:23
If your not experiencing heavy bolt lift, I wouldn't worry about it.

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Tom


Posted By: Graysteel
Date Posted: January/03/2011 at 15:02
Why not just polish the chamber with Flitz (or your preferred brand) metal polish and check the bolt face for squareness? If the problem persists you will at least know those aren't factors.

Cheers.


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