Help ID Problem via Spent Case

[looch]

The image is of 2 cases fired from the same rifle - a sportered .30-06 M1917.

Left is a Winchester Super X 180gr and right is a Federal Premium 180gr. Although it is harder to see, the Federal exhibits the same change in colour about 3/16" up from the rim. The Winchester differs in that the case actually bulges out on one side - I can feel it with my finger. The primer is where it should be, unlike the Federal that is set back about .010".

The inside of the case seems fine, using the sharpened paperclip trick. Really, it's the set back primer that's got me concerned.

 

[H4831]

your rifle has too much headspace. If these were factory loaded cartridges there is not much you can do about it. I wouldn't shoot it like that. I would take it to a gunsmith for evaluation and adjustment.

 

[looch]

your rifle has too much headspace. If these were factory loaded cartridges there is not much you can do about it. I wouldn't shoot it like that. I would take it to a gunsmith for evaluation and adjustment.

What makes you think headspace - the bulge or the primer? Or longer OAL cartridges will bulge while shorter ones will have a primer set-back?

Thanks for your help.

 

[maynard]

Federal cases have big sloppy primer pockets, that's way most reloaders stay away from Federal cases.
Your rifle may have a chamber that is on the large side but still within spec. causing the ring around the Winchester case. The ring is where the case is unsupported when chambered.

 

['Boo]

Really scrub out the chamber of your rifle and try it again.

Head-space may be an issue but a dirty & rusty chamber is more likely.

The "bulge" above the case web is more indicative of a chamber that is a bit "sloppy" in diameter - fairly common on military rifles.

Oh yes ......... the change in "colour" shows the line where the chamber starts. The rear of the case -the shiny bits in your pics - does not enter the chamber and doesn't get marked up when the cartridge is fired.

 

[NormB]

What makes you think headspace - the bulge or the primer? Or longer OAL cartridges will bulge while shorter ones will have a primer set-back?

Thanks for your help.

It does look to me you have a head space problem.

The Winchester brass on the left looks like it moved rearward at the web of the case. That bright ring is more likely stretching lengthwise than an indication of bulging. The case maybe harder in the base than the Federal one or under more pressure and the primer didn't back out taking up the excess headspace space like the Federal case did.. For the Federal case, the primer backed out, and the brass didn't stretch as much in the web, but you will get a bright stretch ring on the next firings if you resize to orginal length.

Try sticking a piece of masking tape on the back (cover the case head) of a new cartridge. The tape is about 6-7 thous thick. If you can put 2 layers or more on, and still close the bolt, then you have excessive headspace.

NormB

 

[b72471]

30-06

What make of action is it, a gunsmith will check out the head space for you. It appears there is a bit of a headspace problem, I've seen worse. If you handload that can be taken into account when resizing brass. Bill

 

[looch]

What make of action is it, a gunsmith will check out the head space for you. It appears there is a bit of a headspace problem, I've seen worse. If you handload that can be taken into account when resizing brass. Bill

As mentioned, it's an Enfield M1917. It's an Eddystone version. The action is a "Mauser-type" rotating bolt with 2 lugs up front.


Thanks for all the tips, guys. I brought it to the range yesterday to see if it would group (it does), but didn't want to go further once I saw the resulting cases. Ulitmately, I want to get rid of it. If there is a problem that requires any amount of money to fix, I will likely have it destroyed.

 

['Boo]

Backed out primers are seldom a sign of excessive head-space, especially in a strong action like the M1917.

What they do indicate is either a low-power loads that fails to set the case back against the bolt face after the case is pushed forward by the firing pin blow or by a rough chamber that also prevents case setback after ignition. As you were shooting factory ammo I don't think the ammo is to blame.

Like I said earlier clean the chamber until it shines and then try shooting it again.

 

[tiriaq]

A couple of minutes and a set of headspace gauges would answer any question about headspace.
There is more than one possible explanation for the appearance of those cases, but the headspace issue is an easy one to check.

 

[looch]

It does look to me you have a head space problem.

The Winchester brass on the left looks like it moved rearward at the web of the case. That bright ring is more likely stretching lengthwise than an indication of bulging. The case maybe harder in the base than the Federal one or under more pressure and the primer didn't back out taking up the excess headspace space like the Federal case did.. For the Federal case, the primer backed out, and the brass didn't stretch as much in the web, but you will get a bright stretch ring on the next firings if you resize to orginal length.

Try sticking a piece of masking tape on the back (cover the case head) of a new cartridge. The tape is about 6-7 thous thick. If you can put 2 layers or more on, and still close the bolt, then you have excessive headspace.

NormB

Ok, I have this green, high temp tape that measures ~.003" thick. I managed to get 10 layers on the head of a cartridge before it was tough to close. To confirm the thickness, I removed the layers of tape and measured them together: .032".

Anything flaws in my method? The only thing that bothers me is that this is a crf action, and I fear that the stiffness in closing may have been because the claw was unable to reach "home" on the rim of the case. But this would just mean that I would be able to add more tape.

What are my options?

Thanks again.

 

[Whelen B]

I'm not a smith but my understanding of the variation between "go" and "no go" is typically about .004". So it would appear to me that you have an extreme headspace condition. That would be consistent with your primer having so much room to back out that .010" as well.

Option 1
Take it to a smith check it again. If the chamber is too long have him set the barrel back and rechamber if necessary (with iron sights he may have to set back a full barrel thread).

Option 2
Otherwise properly fireform brass using a false shoulder or long seating a bullet to the lands and then devote that brass to use in that gun only. Then be careful when reloading not to push the shoulder back more than a .001" or so with your full length sizer.

 

[cosmic]

Your tape results seem to indicate a rather large headspace- bear in mind you could be crushing the tape to a thinner dimension, then it springs back. Perhaps something stiffer would be better.
As mentioned above, reloading offers the simplest solution, if needed. I wouldnt condemn the rifle just yet - get to the ultimate truth.

 

[Why not?]

Backed out primers are seldom a sign of excessive head-space, especially in a strong action like the M1917.

What they do indicate is either a low-power loads that fails to set the case back against the bolt face after the case is pushed forward by the firing pin blow or by a rough chamber that also prevents case setback after ignition. As you were shooting factory ammo I don't think the ammo is to blame.

Like I said earlier clean the chamber until it shines and then try shooting it again.

'Boo,

On the contrary, backed out primers are always a sign of excess headspace! The only reason a primer, or a case, would set back is because of excess headspace.

In the rifle looch has, apparently there is around 30 thou, which is really excessive!

Ted

 

[NormB]

Ok, I have this green, high temp tape that measures ~.003" thick. I managed to get 10 layers on the head of a cartridge before it was tough to close. To confirm the thickness, I removed the layers of tape and measured them together: .032".

Anything flaws in my method? The only thing that bothers me is that this is a crf action, and I fear that the stiffness in closing may have been because the claw was unable to reach "home" on the rim of the case. But this would just mean that I would be able to add more tape.

What are my options?

Thanks again.[/QUOTE

Your method is sound, and you have determined your rifle has around 30 thou.
head space. This is too much. A gunsmith could set it back properly, or as was mentioned you could try reloading new brass and expanding the base of the neck to create a false shoulder 30 thous up from the shoulder. Expand the the entire neck to .338 then resize the top of the neck to .308 to within .030 of the shoulder neck junction. This will keep the base of the brass firmly against the bolt face and the brass should stretch the .030 mostly above the shoulder. A light bit of lube from the shoulder to the neck will help to ensure this. Transfer the lube with your fingers.

You will have longer than normal cases, but they will fit your rifle. Remember when resizing you don't want to resize back to normal, but leave the cases .030 long.

NormB