I have a polish mauser and lately i noticed that the primers backed out the brass on some cases!

The Prvi Partizan look fine but a other brand like the said above!
So i tried to check headspace! I took a case and push the primer half in! Then closed the bolt!
I measured the lengh of the case bevor and after this!
So it turned out that there is headspace between 0,005 and 0,008"! Is this too much? The gun shoots good!
Well i don´t know how accurate this method is!

Do i have to worry or is it ok?

I mean some of the fired cartridges look ok! A gunsmith told me that there are some tolerances and i dont have to worry if the headspace is 0,008"

Thanks so far

David

I wouldnt necessarily trust that headspace check 100%, hopefully you have a smith nearby who can check it with a gauge.

Generally in rimless cartridges headspace shouldnt be more than .003" and you can get away with .005" in belted cartridges.

8X57 I assume...

-Spencer

Hope this helps

Many years ago I had a gunsmith tell me to put four layers of Scotch tape on the head of a factory round and try to close the bolt on the chambered round. If it would close, the rifle had too much headspace. He stated that Scotch tape was approximately .0015" thick, and above .006" was excessive.

However: he also stated that it was fine to shoot a rifle with excessive headspace; all I needed to do was partial length re-size and not push the shoulder of the case back. Staying off the shoulder will ensure the brass doesn't separate at the case head web.

O.K. The advice given is not bad. Never hurts to understand.

When the primer fires it creates pressures, 5K? 10K... who knows. Point is that it blows back out of the case...some... now if you are shooting military ammo with crimped primers, less... THEN as the powder burns and pressures rise, the case is "shoved back" over the primer. If pressures are not "hot" then you don't get alot of deformation. If it is "hot" you get a lot more deformation.

Miliatries are usually "full sized" in the chamber in case the ammo is corroded or oversize or ??? Soldiers don't reload...

As I recall, the headspace is supposed to be, SAAMI, between .004 and .007 or .008. You seem to be on the outer limit. It was the .012 that would usually cause case head separations with hot gas loose to cut things up. At working presssure gas is in the 4,000 degree range. Cutting torches are in the 2,000 degree range.

Since this is not happening with every round, I would not worry, but I am CHEAP. Scotch tape is o.k. You can buy "shim" stock at hardware stores or cut up an old feeler guage. Sticky grease will hold the shim to the rim of a case. .002? .004? .006? I wouldn't sweat. More... As said, if you don't full length resize, then the case will not lengthen fast and should not pull apart. If you over full length resize, you can create this condition.

If you are just playing with surplus ammo, have fun. If you reload, allow. And when the gun moves on... warn the next person. luck.

the scotch tape thing is an old gunsmiths trick. and it does work

Yeah but there ain't too many old gunsmiths around anymore.

Set the barrel back or rechamber to 8mm/06.

[QUOTE]Originally posted by david.30-06:
I have a polish mauser and lately i noticed that the primers backed out the brass on some cases!

The Prvi Partizan look fine but a other brand like the said above!
So i tried to check headspace! I took a case and push the primer half in! Then closed the bolt!
I measured the lengh of the case bevor and after this!
So it turned out that there is headspace between 0,005 and 0,008"! Is this too much? The gun shoots good!
Well i don´t know how accurate this method is!

Do i have to worry or is it ok?

I mean some of the fired cartridges look ok! A gunsmith told me that there are some tolerances and i dont have to worry if the headspace is 0,008"

Thanks so far [QUOTE]



David

I don't think the question can be answered with the information you give. Clearly it is best if you know what the headspace is and if it is safe.

If you use a fired case from the rifle in question with a primer that can be pused in, you will not be measuring the headspace. The fired round should expand and a new primer in that case would fully seat. In fact, no matter how excessive the headspace, the once fired cases would just fit the chamber. This case could be reloaded without resizing and would be safe no matter what the headspace. This is how the many "improved" rounds were first made. If the headspace was excessive, the once fired and reloaded but not resized rounds may not fit in a standard chamber.

If you used a fired case from another rifle, you are only comparing one chamber with another, not measureing headspace. If you are using a fully resized case or a new from the box case with the bullet pulled, well it depends on how much that case was below the minimum SAAMI specs. The only way to be sure that the headspace is correct is to use precision gauges.

The min and max listed are standards for manufacturing, they are not the min and max safety standards. The military even pushed their "field" out to I think ~12 thou over. If this is a rifle you want to shoot frequently and keep, then have it checked properly. If you are only going to use it occasionally you should not feel that having the primers back out a bit puts that rifle out of service. If you shoot infrequently and you neck size the cases (and you don't try to shoot them in another gun,) you can shoot a gun with a bit of "excess" headspace quite safely.

Roger

It's a bit bothersome that you say the headspace is between .005 and .008.....that's a bit too much to not know about because it makes me wonder how accurate you are

The method you described should yield a single number...X-Y =..... but you list a range.

Personally, if you're convinced the headspace is not greater than .008 I'd back off my FL die .008 and resize to match the chamber.....

This eliminates the headspace issue.....and I really don't think there's much to be concerned about with a Military rifle with a total headspace of .008.

the supposedly "excessive headspace" is not a problem if you deal with as described by a few here,... namely just back off the die and neck size the cases that have been essentially "fire-formed" to your gun's chamber. then make sure you only use those cases in that gun. if done that way, the head space just means a very slightly larger case volume.
the concerns look at "how did the headspace get there?". if a product of sloppy war time production, then "so be it" and carry on with the above method of relaoding for that rifle, it will probably never change and the minimum and maximum standards are only related to the standards of factory produced ammo being used safely in a wide range of gun brands but, make sure there is no set-back going on first. a soft action will continue to set back to dagerous conditions.

Thanks guys for your replys!
I took the gun today to a gunsmith unfortunally he didn`t had the gauges for 8x57is but he said he wouldn´t concern much!
It is a polish PFK Warzawa 1926 rifle small ring/large thread! I heard that they used good steels! The bolt is not matching the action!Maybe a other bolt is better?
How can i figure out if there is lug set back!
Do i have to pull the barrel, or is there a other method!

Regards David

My understanding on military mausers is if it will not close on a field gauge it is ok. It is also possible to change bolts to change head space.

Rad

If after firing a round the bolt is difficult to lift to open the action then you may have setback.....or a lot of it....if on the other hand it lifts normally then you can assume you have non e or very little of it.

as long as you fire American made factory ammo in this gun it is extremely unlikely you'll ever increase any setback you now have nor if you have none now, will you incurr any.