Case Head Separation

[hylander]

This is a first for me in over 24 years of reloading and 47 years of shooting.
Just sharing an experience.
Rem 700, 30-06
Not from a hot load, all remaining loads were pulled and all components
are spot on.
Brass: Remington
Bullet: 165 Sierra 165HPBT
Powder: 45.5 3031
Primer: WLR
These were two rounds back to back, stopped shooting after this.

I believe two things are going on.
First: Checked headspace, Closes on No-Go gauge.
Second: Some of the brass I have been using has probably been loaded more than a dozen times (mostly cast loads) as I was not keeping track.
Just a side note: this has nothing to do with the issue at hand but this barrel also has way to much free bore, with the bullet seated out to 3.350 which is more than normal, it still has .070 jump to the lands.

Anywho,
Looks like I might be ordering a new barrel as it is only a couple hundred more than having this one set back and rechambered and then hope it is good.

[jpg366]

Lots of hot loads? What shape are the lugs in? May be wishful thinking to blame the barrel.


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[xfer42]

Could be the barrel and die combo stressing and hardening the brass too much. I would just shoot them and see whats left, personally. It is embarrassing if you are at a range and having to clear your firearm and explain "Oh, yeah, I reloaded these".

[hylander]

No hot loads ever fired.
Not going to shoot rifle until issues with barrel are corrected

[ar15barrels]

I believe two things are going on.
First: Checked headspace, Closes on No-Go gauge.

It IS acceptable for a used rifle to close on a NO-GO gauge.
It is NOT acceptable for a used rifle to close on a FIELD gauge.

You might already be set on getting that new barrel anyways, but without having checked with a field gauge, you don't actually know if your existing chamber is long or not.
Even if it IS long, adjusting the dies will create ammo that matches the gun so the brass does not stretch out so much with each firing.

When you reload, you can adjust your dies to size the case closely to the chamber length.
This might make ammo that has a longer shoulder than NEW ammo, but as long as it fits your gun nicely, it will work good.

Your case head separation is from years of sizing that brass MORE than you needed to.
If you continue this bad sizing behavior with a new barrel, you will get the same results.

[ar15barrels]

Not going to shoot rifle until issues with barrel are corrected

Without checking with a FIELD gauge, you can't actually make a determination that the barrel is the problem.

[hylander]

This is brass that was never fired from this rifle until this outing. This brass was always fired from rifle with minimum headspace, it was never over sized, just sized to many times.
I would just sized it to match the chamber but I have another 30-06 to load for and don't want to have seperate brass. I could set the barrel back but i kinda just want a new barrel anyway.

[hylander]

Without checking with a FIELD gauge, you can't actually make a determination that the barrel is the problem.

True.
I think it is more of the brass being reloaded to many times. But the barrel does have to much headspace than I would like and way to much freebore.

[divingin]

This is brass that was never fired from this rifle until this outing. This brass was always fired from rifle with minimum headspace, it was never over sized, just sized to many times.
I would just sized it to match the chamber but I have another 30-06 to load for and don't want to have seperate brass. I could set the barrel back but i kinda just want a new barrel anyway.

Separation (or rather leadup to separation) occurs when you fire a short case in a long chamber. When fired, the case mouth grips the wall of the chamber, but the base doesn't (due to thicker brass), and the case stretches to drive the case head against the breech. it generally thins the brass right where yours separated.

Separation can be physically dangerous (to the shooter), as the leaked gas has to go somewhere; exactly where it goes depends on how the rifle is designed. You also run the risk of metal damage from the gases etching the chamber or action (or worse.)

In any case, your scenario is perfect for that to occur: Your rifle has a very long headspace measurement, and you are shooting brass sized for a minimum headspace chamber. End result: The brass is too short for your rifle, allowing the brass to stretch and separate.

You will need to separate brass for the two rifles unless you can set the headspace measurements the same for both.

[Fjold]

Separation (or rather leadup to separation) occurs when you fire a short case in a long chamber. When fired, the case mouth grips the wall of the chamber, but the base doesn't (due to thicker brass), and the case stretches to drive the case head against the breech. it generally thins the brass right where yours separated.

Separation can be physically dangerous (to the shooter), as the leaked gas has to go somewhere; exactly where it goes depends on how the rifle is designed. You also run the risk of metal damage from the gases etching the chamber or action (or worse.)

In any case, your scenario is perfect for that to occur: Your rifle has a very long headspace measurement, and you are shooting brass sized for a minimum headspace chamber. End result: The brass is too short for your rifle, allowing the brass to stretch and separate.

You will need to separate brass for the two rifles unless you can set the headspace measurements the same for both.

This!

[hylander]

Thanks for all the input.
Was going to just set the barrel back and rechamber, but my wife says buy a new barrel
Also, already took all that brass out of battery and replaced with new brass.

[divingin]

Was going to just set the barrel back and rechamber, but my wife says buy a new barrel

Hey, gotta listen to the wife...

[hylander]

Hey, gotta listen to the wife...

You know it,
Cause if Momma ain't happy, no body's happy

[saki302]

Randy at R&D showed me once, that a lot of factory remington rifles will close on a no-go gauge. Including mine. He turned the barrel back a bit more than one turn and rechambered it tighter for me.

As Randall said above, the test is the field gauge. If it passes the field but fails no-go, it probably came out of the factory that way, and is fine. If you rebarrel or recut the chamber though, your brass will last longer if you full length size. If you neck size only and marry it to the rifle, it makes no difference at all.

[ar15barrels]

Randy at R&D showed me once, that a lot of factory remington rifles will close on a no-go gauge. Including mine. He turned the barrel back a bit more than one turn and rechambered it tighter for me.

The more-than-one-turn setback was not primarily to fix headspace.
Headspace could be fixed by surface grinding a couple thousandths off the lug and leaving the barrel alone.

That setback job was to be able to re-cut the chamber with a slightly better throat.
The headspace can be shortened up at the same time though.
1 turn is 1/16" so he was getting rid of some of the excessively long factory throat primarily and secondarily re-setting the headspace.