Which GO/NOGO should I GO with??

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noonxnoon

Which GO/NOGO should I GO with??

Postby noonxnoon » Sat Dec 20, 2008 12:18 pm

Ok,

Looking at a site that has GO/NOGO tools that I want to get for my 53(still waiting on).

I see two different brands/styles and looking for advice on these items and if it is good or look elsewhere.

http://www.brownells.com/aspx/NS/store/ ... E%20GAUGES

Here I didn't see a direct 8mm Mauser, just 8mm mag, 8mm-06 for the GO-NO GO


http://www.brownells.com/aspx/NS/store/ ... E%20GAUGES

Here I see a literal 8mm Mauser with a GO-NO GO, and a 'Field' item.

What is that 'Field' item and is it valuable? I am thinking to getting all three of the above item in 8mm Mauser

thanks

MGMike
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Re: Which GO/NOGO should I GO with??

Postby MGMike » Sat Dec 20, 2008 2:58 pm

High Noon :D

Most places call the German service round the 8mm Mauser. So, you are looking for gauges, etc. for that, or 8x57....another way they are sometimes listed.

You will want the Go and the No-Go gauges. The Field gauge is more of an "it's wore out" gauge. Your bolt should close on the Go gauge, but not on the No-Go gauge. If the bolt closes on the Field gauge, it's time to rebuild the gun :(

Hope that helps.

MikeD

shinsoku

Re: Which GO/NOGO should I GO with??

Postby shinsoku » Sat Dec 20, 2008 3:12 pm

Maybe I can help here a bit. I have headspaced a few guns in the past. The last being a DeLislie carbine that I built. Really all a guy needs is the no-go guage and and dummy round. Good dummy rounds are made to specs. and are cheaper than a go guage. THINK SAFETY FIRST. A live round with the bullet hand pulled and powder and primer removed and bullet re-seated will work for a go-gauge. Never have live rounds around a gun you are working on. Dummy rounds are kind of a must really. For cycling the action etc. So just use them and forget the live round senerio. I have used both Fostner and Clymer gauges. Both are good and made to specs. First you have to keep in mind the length of the chamber. With the no-go-gauge inserted in the chamber basically the bolt should not (lock up) close completely. This would be the maximum chamber depth. Or unsafe chamber length. With the dummy or go-guage inserted the chamber. The bolt should lock up. "A safe chamber". The distance between the no-go and go gauge is the acceptable tolerances to fire the gun. The 8mm mauser is the same as the 8x57mm or 7.92x57mm etc. Hope this helps................

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Re: Which GO/NOGO should I GO with??

Postby DARIVS ARCHITECTVS » Sat Dec 20, 2008 3:14 pm

8mm-06 and 8mm magnum are the wrong size, so don't bother getting them. There are 8mm gages out there, it's just that they are hard to find. The main stores don't carry them anymore. You need 8mm Mauser. And, when you find them, you should buy all three: GO, No-Go, and Field.

Go is the smallest length. If the bolt on a rifle or the MG-42 bolt closes on a Go gage, then the head spacing is OK. If the bolt will NOT close, then the headspacing is TOO TIGHT and the firearm is NOT safe to shoot. You MUST be able to fully lock the bolt when a cartridge is in the chamber.

No-Go is intermediate length. If the bolt closes fully without interference on a rifle with a No-Go gage, then the headspacing is too large and the rifle MAY be dangerous to shoot, and probably if you do, the casing of the round will be overexpanded and useless for reloading. My MG-42 does close on a No-Go Gage and works fine, and I think that the tolerances are loose, and that the MG-42 is probably safe to shoot.

Field gage is the longest gage, and the one used to tell you that the headspacing is so large that the firearm (rifle or machinegun) is NOT SAFE UNDER ANY CONDITIONS to shoot. If the bolt closes on this gage, the gun should not be used! If the headspace is large enough for the bolt to lock down on this gage, then the headspacing is so large that you will probably always split or break the shell case, which will allow escape of high temperature, high pressure gasses out of the rear of the gun, and probably into your face.

Gas escape in smaller amounts, will erode and pit the face of the bolt. On old guns, you may notice a ring of pits corresponding to the diameter of the primer pocket on a cartridge. This will show you what happened when a bit of gas escapes from the rear of the cartridge around the primer. And it can happen without blowing the primer out the back of the cartridge. Over time, leaky ammo primer pockets cause this ring of erosion pits, especially on old military guns that have seen a lot of use and have used military ammo. I have seen this pit pattern of several of my MG-42 bolts and some k98 rifles. If headspacing is too large, the gas escape will be huge because of a ruptured case, and the shooter is in danger of serious injury.

Keep looking for 8mm Mauser gages. All collectors of old Mausers and machineguns SHOULD have them, and when you buy a new (old) gun, you should check them for headspacing BEFORE shooting them the first time. If you can't get the gages, had a local gunsmith check the headspace for you. They almost always have the correct gages, because any gunsmith worth his salt would have sooner or later worked on an 8mm Mauser.
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noonxnoon

Re: Which GO/NOGO should I GO with??

Postby noonxnoon » Sat Dec 20, 2008 3:37 pm

Thanks for the quality answers guys.

Really appreciate it.

I'll go for the 8mm mauser parts.

I'll need it for the 53 and I plan on getting some sort of C&R bolt action 8mm as well.

Maybe this bit can be made a sticky or a part of a general sticky.

shinsoku

Re: Which GO/NOGO should I GO with??

Postby shinsoku » Sat Dec 20, 2008 3:49 pm

I am very glad to help out. I am very new to this forum. But have gleaned more info from this site for my 34 build than I could have found in two years on my own. Cheers................

Mike

Re: Which GO/NOGO should I GO with??

Postby Mike » Sat Dec 20, 2008 9:19 pm

What are planning on "head spacing"?
Barrels and bolts have the "head space" built in by the factory.
Unless you see ALLOT of wear, the bolt-barrel combination should work.

Also, the present 8mm head space gages have different dimensions than the german ones form the 30s and 40s.

Todays head space gages are per the SAAMI spec and are for "new" ammo and "new" rifles.

Also, machine guns like the M249 have different head spaces gages that are longer than the M-16A2 gages.
New MG-3 bolts and MG-3 barrels will close on field gages, I think they were about .020 " longer

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Re: Which GO/NOGO should I GO with??

Postby tomcatshaas » Sun Dec 21, 2008 10:46 am

noonxnoon wrote:Thanks for the quality answers guys.

Really appreciate it.

I'll go for the 8mm mauser parts.

I'll need it for the 53 and I plan on getting some sort of C&R bolt action 8mm as well.

Maybe this bit can be made a sticky or a part of a general sticky.



There's already a sticky in the sticky section on headspace !!!!!!!!

It even has pictures so DA can understand it.

viewtopic.php?f=39&t=4907

TC

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Re: Which GO/NOGO should I GO with??

Postby DARIVS ARCHITECTVS » Sun Dec 21, 2008 12:26 pm

Sorry TC, I forgot you had already tutored us on the topic. TC's post is pretty thorough. Love the pics too.
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Re: Which GO/NOGO should I GO with??

Postby noonxnoon » Sun Dec 21, 2008 2:07 pm

Thanks for the info Tomcat.

only thing in my defense was I had specific products to get advice for as well as what it all meant!

:)

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Re: Which GO/NOGO should I GO with??

Postby DARIVS ARCHITECTVS » Sun Dec 21, 2008 3:03 pm

Hey TC, I added a MS Word version of your article to the Sticky. Please review it for correctness and get back to me. Attached here is another copy of it. Guys, print this article on your color printer.
Attachments
Checking the Headspace in the MG-42.doc
Checking the Head Space in the MG-42
(1 MiB) Downloaded 40 times
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Re: Which GO/NOGO should I GO with??

Postby Bil » Mon Dec 22, 2008 7:50 pm

I am out of cyan ink-I hope to get some for Christmas.I used the old black and white copier and colored it with my crayons-it looks pretty good except where I went out of the lines.I would have used those nice colored pencils,but the doctors said I am not ready yet.Thanks for the info,DA! ---bil
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noonxnoon

Re: Which GO/NOGO should I GO with??

Postby noonxnoon » Mon Dec 22, 2008 9:14 pm

Mike,

The main use for the GO/NOGO is for a 'new' M53...so I am guessing the gauges would be fine for that.

I am also planning on getting an 8mm mauser bolt action. A C&R one...so over x amount of years old.

You think it would be unreliable for the older rifle?

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Re: Which GO/NOGO should I GO with??

Postby DARIVS ARCHITECTVS » Mon Dec 22, 2008 9:41 pm

Bil wrote:I am out of cyan ink-I hope to get some for Christmas.I used the old black and white copier and colored it with my crayons-it looks pretty good except where I went out of the lines.I would have used those nice colored pencils,but the doctors said I am not ready yet.Thanks for the info,DA! ---bil


You went outside the lines ? :lol: Shame on you.. at least you didn't use a bloody stump this time..
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Re: Which GO/NOGO should I GO with??

Postby MGMike » Mon Dec 22, 2008 11:03 pm

noonxnoon wrote:Mike,

The main use for the GO/NOGO is for a 'new' M53...so I am guessing the gauges would be fine for that.

I am also planning on getting an 8mm mauser bolt action. A C&R one...so over x amount of years old.

You think it would be unreliable for the older rifle?


No, the gauges should be fine. They are the ones that a gunsmith would use to check your Mauser for safe headspace. The deal's the same, especially if you're figuring on shooting the Mauser.

MikeD


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