Head space issue?

J

Jwilson904

New member
I think my chamber is bad in my mid 90s remington 700. First I was having case head seperation on the 2nd firing occasionally with Remington brass originally fired in the rifle as factory loades. So I bought some new Norma brass and loaded 5 of them without sizeing. Shot 4 of them at the range today and I can see the case is almost cracked right above the head.

Do I need a new a barrel?
 
...new Norma brass and loaded 5 of them without sizeing.
Shot 4 of them at the range today and I can see the case
is almost cracked right above the head.
Click to expand...
Yup... hie thee to a gunsmith for a headspace check.


BTW: What is the fired case length vs unfired/new Norma brass ?
 
That is pretty amazing.

New gun to you or have you owned it all along. Caliber (not relevant exactly but helps get our brains around the setup)


Keep in mind head space is not likely the issue, chamber yes, but that is more than head-space.

I shoot guns that I change barrels on, if your head space gets too long the rounds simply will not fire and the action of sizing back is what cracks them but that tends to take 5-6 rounds if its a full shoulder setup aka the recommended cam over most die and press mfgs say to do.

The reason too long a head space stops the ignition is the shell travels forward as the firing pin hits the primer and it does not impact the primer with the immediate force needed to make the primer explode. You can have a significant dent but that dent is formed by slow action over time as its all happening. You need a sharp smack which if done right the case move forward a tad and then POP the primer gets pushed down into the anvil and the firing pin form the required OOOMPH that makes it go bang.

Yours is not that issue so its not head space.

Unclenikck probably has idea on a chamber that is too large an OD and if that can cause it in your application.


How recently did you start reloading?
 
RC20 said:
That is pretty amazing.

New gun to you or have you owned it all along. Caliber (not relevant exactly but helps get our brains around the setup)


Keep in mind head space is not likely the issue, chamber yes, but that is more than head-space.

I shoot guns that I change barrels on, if your head space gets too long the rounds simply will not fire and the action of sizing back is what cracks them but that tends to take 5-6 rounds if its a full shoulder setup aka the recommended cam over most die and press mfgs say to do.

The reason too long a head space stops the ignition is the shell travels forward as the firing pin hits the primer and it does not impact the primer with the immediate force needed to make the primer explode. You can have a significant dent but that dent is formed by slow action over time as its all happening. You need a sharp smack which if done right the case move forward a tad and then POP the primer gets pushed down into the anvil and the firing pin form the required OOOMPH that makes it go bang.

Yours is not that issue so its not head space.

Unclenikck probably has idea on a chamber that is too large an OD and if that can cause it in your application.


How recently did you start reloading?
Click to expand...
30-06. I bought the gun new. The brass measures.003 longer using a hornady comparator. And the case head measure .003 larger after firing. Thanks for the help
 
RC20 said:
What specific aspects of reloading would cause that with one firing?
Click to expand...
The OP said the separation did not happen on the factory firing but on the first reload. If the rifle has excess headspace you can have the barrel rechambered/replaced or you can size your cases to match the chamber they were fired in.
 
The OP said that his first loads (agreed they are reloads) of NEW non fired Norma Brass cracked.

Where I fall off the edge is the .003 growth in diameter.


Norma brass is the best brass out there. I have seen (can't find it) test with Norma and other brasses and it beats Lapua for longevity.

If it cracks Norma Brass, there is a non head space issue. RP is about even with Lapua in my experience, interesting it survived a few firings.


Nothing wrong with the head space of .003 growth. Totally normal. Again if the head space (real head space) was excessive, they simply would not fire. I been there and done that.

I now use specif brass for the 1917 (also 06 by the way) and it just grows to fit the chamber and minimum set back and it does fine.

I have fired full resized brass in a Model of 1917 that did not crack until 5 reloads. That gun truly has excessive head space.

The only cambering I have heard of doing similar to the OP is the 303 in a SMLE. Lucky to survive one firing. Large chamber for combat.
 
"...new Norma brass and loaded 5 of them without sizing..." BNIB brass is not ready to load from any manufacturer. That is not a reason to require a new barrel though.
A headspace issue is a possibility. You having extraction issues too. How difficult is it to open the bolt?
Mind you, 3 thou is a lot of case stretch, even though cases stretch the most on the first firing. So you might have an oversized chamber. Isn't likely though. This something new that started recently? An oversized chamber would have caused issue right from the get go.
In any case, you need to take it to a smithy.
"...using a Hornady comparator..." Isn't how you measure case lengths.
"...too long a head space stops the ignition..." Nonsense. The extractor will hold the cartridge against the bolt face.
 
30-06. I bought the gun new. The brass measures.003 longer using a hornady comparator. And the case head measure .003 larger after firing. Thanks for the help
Click to expand...

The case head increases in diameter .003" when fired? That is 15 times as much case head expansion as there was before the Internet; today we got so many people making stuff up and then there are all of those claims made about cases being soft like FC.

The case head expansion for new factory ammo at one time was .00025", after that someone made4 up a deal that claimed the .00025" expansion was for each firing meaning it would require 4 firings to expand the case head .001". I have always disagreed because I can not have it both ways, the case when worked hardens so I would not thing it is practical to go beyond one firing, after one firing start on another new factory case.
 
I have only exceeded 0.003" or greater case head expansion once in my entire life.

That one pretty much ruined the case and the primer pocket.
 
Y
 
That would be the rim diameter. As Mr Guffey says, I measure before and then again after.

I guess that wouldn't be case head expansion, but case head expansion went way overboard as well. I don't remember the measurement, but I could dig that case out of the archive if it is important to the cause.

And it is the diameter. Horizontal axis would have no meaning as most cases lengthen after firing. Some don't.
 
30-06. I bought the gun new. The brass measures.003 longer using a hornady comparator. And the case head measure .003 larger after firing. Thanks for the help
Click to expand...

Lets be clear, after firing a case for the first time the case in .003" longer, over all. Right??

That's not a big deal. New brass often stretches (and stretches most) on its first firing.

The case head measuring ".003" larger" bothers me. To be clear, are you saying the case head (the solid part just ahead of the extractor groove) is .003" larger in diameter after firing?

If so, this is a very NOT GOOD thing. And it would account for early case failure. .003" is 3 times the .001" limit generally accepted as max allowable case head expansion.

.003 case head expansion is BAD, and something a "standard" headspace check may not even see.

The regular heaspace gauges (GO, NOGO and Field) only measure distance from the bolt to the chamber shoulder. If your chamber is that large in diameter (allowing .003" case head expansion at normal pressure) a headspace gauge check (.30-06) won't see it.

To be certain, you need to have a chamber cast made. If the chamber cast shows your chamber to be grossly out of spec (and that's what .003" head expansion with factory loads sounds like to me) THEN you need to talk to the gunsmith and Remington.

Remington, to see if despite the time that has passed, it is a warranty matter. (the most they can do is say "no", right?)

IF your chamber is bad (oversize) there are two options. Replace the barrel with new, or pull the old barrel, cut off enough of the chamber end that it can be rechambered and rethreaded, and reinstalled on the action. (this is not always a possibility, but is possible, sometimes, depending on how much of the original chamber has to be removed to "clean it up" so it can be re-chambered.

Get a chamber cast done, or do it yourself, and measure carefully, to get an idea.

And, remember that despite what we all feel ought to be, and what usually is, a gun isn't "broken" if it fires each round once, without case failure.

Good luck, and please tell us if its really .003" case head expansion, or not..
 
Yes the case head right above the rim measures .003 larger than an unfires case . Pretty sure that is my problem. No the case length is not .003 longer the shoulder is bumped out .003 after firing.

I will definetly get a new barrel in stalled probably an after market barrel. Now I just need to find a good gunsmith in my area.

Thanks for all you guys help.
 
If it does not go back to Remington I would go with what they call a Remage barrel.

Its the same setup as Savage with the Remington threads and a nut. It saves a lot of Gun Smith costs (they don't have to do threads nor chamber work, you adjust the head space via the screwing in of the barrel)

Once the original barrel is off with about $125 or so in tools you can take the barrel off and put a different one on or be able to replace the barrel down the road if you shoot it out (obviously not a hunting thing, target thing but I do shoot 30-06 target)

Note: Not having gotten into base expansion I had no idea what was excessive. Good to get that nailed down.
 
Thanks RC i looked at the remage barrels and would do it my self but am afraid of removeing the old barrel. Do most stocks work with the remage barrel nut?
 
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