Checking Headspace

L

Lichtfuss

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I tried doing a few searches but i couldn't find an answer to my question.

When buying a military surplus rifle, does everyone always check their headspace before they shoot it for the first time? I want to know what the general opinion is on this topic. Also, to check headspace, is a guage set required or has someone come up with a home-brew method?

Thanks
 
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Don't know if it is necessary. Not a bad idea, though, if a Field gauge is available. A gauge set is not necessary. Keep in mind that the specs to which a rifle was manufactured may not be the same as the specs to which a modern gauge is ground.
There are some improvised methods.
You can learn a lot by sectionning the head of a case fired in the rifle. If there is an incipient separation, it would be worth checking it out.
 
I made a go and a no go

I made headspace guages for mosins took about 20 min with a lathe, mill and surface grinder. But yes you should check especially if the gun has mismatched parts.
 
I do not, but on all Lee Enfield No.IV Mk.I's I look at the bolt head number. I usually do not headspace if it is in good condition. For my Martini-Enfield I used a feeler gauge (15 bucks, Canadian Tire) to check headspace.
 
Bolt head numbers on a No. 4 do not tell you anything about the headspace of a particular rifle.
When a rifle was manufactured, it is pretty safe to assume that it was within whatever tolerance limits were established by the manufacturer.
If significant wear has occurred, or if parts have been swapped, things may have changed.
I have tested a quantity of Swedish Mausers with a SAAMI No Go gauge. These rifles were as issued with matching bolts. Every one accepted the No Go. The only 6.5x55 rifle I found that would not accept the No Go was one of the Danish Mauser military target rifles built up on a M98 receiver. A Field gauge will tell you if tolerances are on the generous side.
 
Only headspace guages tell you anything. A No-Go and a Field is all you need. Unless you change barrels. Then you need the Go as well.
Always check Lee-Enfields. You have no idea if the bolt head has been changed at some time. Matching serial numbers is no guarantee of good headspace either. The other thing you'd want to do with a Lee-Enfield is slug the barrel. Headspace first though.
 
sunray said:
Only headspace guages tell you anything. A No-Go and a Field is all you need. Unless you change barrels. Then you need the Go as well.
Always check Lee-Enfields. You have no idea if the bolt head has been changed at some time. Matching serial numbers is no guarantee of good headspace either. The other thing you'd want to do with a Lee-Enfield is slug the barrel. Headspace first though.
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Absolutely! ALWAYS have the headspace of any milsurp rifle checked by a competent gunsmith familiar with the model in question.
 
No, just shoot the darn thing. Just check the brass afterwards for untoward case seperation. There are thousands of .303 LE rifles here in NL. I bet 98% of them have never had the headspace checked.
 
Here is a story about excess headspace from Bob Greenleaf, who is a retired Savage engineer. He designed the post-Brewer version of the 110 action.
Bob took a 110 off the line in .30-06. With the lock nut breeching sytem the experiment was easy to do. All firing was done under controlled conditions.
He proceeded to fire the rifle, unscrewing and locking the barrel between shots. The headspace was increased in controlled stages, starting with standard. He stopped the test when it was impossible to get the rifle to fire any more, because the cartridge was so far away from the boltface and the firing pin. That is, headspace was grossly excessive.
The results of this experiment?
Nothing happened. Every case fireformed. No cases failed. No head separations.
Now, this test was conducted with fresh commercial ammunition.
No cases were reloaded, nor were they suitable for reloading. The ones from the later stages of the testing were stretched.
Does this mean that headspace doesn't matter? Of course not.
It is desirable that a firearm be within tolerances. If a cartridge case separates, some actions do not handle the situation very well.
Ever had a case separation in a .303? If you handload you probably have experienced this. Did anything happen, apart from the front of the case being left in the chamber? Was there a catastrophic release of gas? Or did you not notice until you tried to chamber the next round?
By all means, have each and every firearm you own checked for headspace, both commercial and military.
 
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