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Say you want to check your Mauser Headspace

Posted: Mon Jul 04, 2005 3:44 pm
by Niner
What you need is a field gauge and some of these very flat pliers to take the extractor off. If you don't remove the extractor you may get a false reading.

http://img.photobucket.com/albums/v51/N ... P_2530.jpg[/pic]

Posted: Sat Jul 09, 2005 1:41 am
by sunray
"...If you don't, you may get a false reading..." Um, no. All you need is the guages. Taking out the extractor is not required and takes too much time. Just slip the guage under the extractor and close the bolt. If it closes on a No-Go, the headspace is bad. However, try the 'Field' guage. If the bolt closes on a 'Field' guage, the rifle is unsafe to shoot.

Headspace guages don't measure anything. They only tell you if a particular rifle is within specs.

Niner, with respect who tells this stuff?

Posted: Tue Jan 03, 2006 11:26 am
by spearedum
Is excessive headspace because of a faulty bolt or a bad chamber? Ergo, (what ever that means), can you fix a mil surp with excessive headspace?

Thanx Dante' :CA: :salute:

Posted: Tue Jan 03, 2006 12:26 pm
by Brass Rat
If it's not too far out you can just fire form some brass for it and blast away.

Beyond that about you can do is set the barrel back 1 thread and ream the chamber.

Posted: Tue Jan 03, 2006 1:03 pm
by spearedum
So it not the bolt, but a worn or streached chamber? I have a 88 Kommission .318 Chinese mil surp that the seller stated had excessive headspace. The bore is shiney without any frost, the bolt does not match. I just wondered if it could be repaired to a shooting condition?

Thanx Dante' :CA: :salute:

Posted: Mon Oct 13, 2008 10:21 pm
by sc928porsche
Excessive headspace can be caused by several things. Streached or worn bolt lugs, worn lug contact on reciever, different bolt, or worn chamber. Since the bolt #s dont match, It is most likely the problem. To be certain, take your rifle to a smith and he can determine if you have excessive headspace and correct the problem before you attempt to fire it.

Posted: Tue Oct 14, 2008 3:14 am
by andrew375
Yes, you have to completely strip the bolt, this is because you need to "feel" the bolt closing. As soon as you feel ANY resistance that is when you've made contact with the gauge. The no-go gauge will not necessarily prevent the bolt from closing, this is because the locking lugs are usually cut on a slight helix or have an inclined leade to facilitate bolt closing and extraction. The mechanical advantage provided will compress the gauge and any resistance from either the extractor or firing mechanism will swamp the "feel" needed to properly use the gauge. All this is covered in Hatcher's Note Book and in the instructions from the gauge manufacturer.

BTW, if you do force the bolt closed on a gauge then it is scrap.

Very few so called gunsmiths know how to use headspace gauges and I am appalled at the number of "custom" gunsmiths who do not even possess any at all. As a favour for one of these toss pots I made him a set of head space gauges for a rifle he was working on. He promptly dropped the no-go gauge into the chamber and slammed the bolt shut. The idiot was amazed that I dropped the gauge into the waste bin and more than a bit upset when I told his customer to take the rifle somewhere else.

I would like to add

Posted: Tue Oct 14, 2008 11:19 am
by Niner
Use only two fingers and light pressure when turning a bolt on a gauge. As soon as you feel resistance that's the answer you are looking for...as andrew373 pointed out.

Posted: Tue Oct 14, 2008 10:32 pm
by Aughnanure
It is worth remembering that most, if not all, rimless 'improved' calibres must have excess headspace to be 'improved'.

Brass Rat is quite correct, fireform your cases and keep them for that rifle only..

See also 'Headspace Hokum' by Parashooter over on 'Enfield Rifles of the World'

http://collectorguns35625.yuku.com/topic/1330 and have a read of the following posts.

Posted: Wed Oct 15, 2008 3:18 am
by andrew375
Aughnanure wrote:It is worth remembering that most, if not all, rimless 'improved' calibres must have excess headspace to be 'improved'.
Incorrect! The definition of an "Improved" cartridge is that whilst case volume has been increased, usually by blowing out the body taper, the headspace remains the same. The reason for doing this is so factory ammunition can be safely used in the event of you not having any of the correct ammunition and to make fireforming easy.