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Old September 14, 2008, 04:07 PM   #1
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Mauser bolt concerns

Hi All,
New to the site.
I have a question reguarding a Mauser 98. I inherited a mauser 98K from my father. He was in the middle of sportizing it when he passed away. It has a Bell and Carlson stock, aluminum hinged flooplate with antelope engraving. He purchased a turned down bolt off ebay.

I would like to finish off the project and use it in memory of him. My issue is when I test fired the rifle it shot fine without and signs of stress on the action or barrel. But when I go to open the bold it is very stiff and I have to literly slap it in order to bring the bolt upward. I've worked the action with rounds in to see if was the headspace was compromised with the new bolt. But every round loaded and ejected properly. It was olny when it was fired tha it siffened up. There was no tiggerwork done on the rifle. Not certain if it ever was checked for porper headspaceing though.

Any suggestions or advice is appreciated!

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Old September 14, 2008, 04:12 PM   #2
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What are you shooting?

I have a Yugo Mauser and when shooting Turk ammo I get the same results. That stuff I fairly hot loaded. I also split a bunch of brass necks.
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Old September 14, 2008, 07:17 PM   #3
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If it's a "stock military Mauser" it could be a rough or rusted chamber.
Mausers (and millions have been made) are basically interchangeable unless you get some "short" Mausers. They (most of them) have had thousands of rounds through them and most have a very fine pitted barrel and sometimes a chamber.
I would have headspace checked and that chamber polished. I doubt that it's headspace as I've found Mausers with .020 headspace and it doesn't hinder ejection - but definately get your headspace checked.
It's true some old ammo will crack and carry on but I don't think it's ammo.
Harry B.
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Old September 14, 2008, 07:22 PM   #4
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Did you feed the rounds through the mag or drop them into the chamber. You'll get that result from dropping them directly into the chamber.
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Old September 15, 2008, 03:23 AM   #5
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All the suggestions so far are good.
One source of a difficult to open bolt is excessive pressure.Its not the only possibility,but if that is what is going on,it is important to know .
Possible sources of excessive pressure could be preservative grease in the bore,or a fresh blue job,if it is an 8mm ,read about JS and J series bullets,the earlier 8x57 was a larger dia and can cause pressure.
The Mauser cams the firing pin spring back on bolt opening.You are overcoming that force.As it is a new bolt,the assembly of the cocking piece and bolt and cam and the threads inside the bolt might need cleaning,lube,or just a touch of fitting.It may have been fitted with a lo safety which sometimes needs a bit of gunsmithing and could cause problems.Some of those safeties lock the bolt shut if not fitted just right.It is basic Mauser mechaniking!!
I know that aluminum guard very well!! When you go to remove it from the stock,be very careful!!Especially if it has been glass bedded.If you put your fingers in the guard bow,and just pull it out of the stock,the little boss around the front guard screw will bind just a bit in the stock.If ,when it comes out,it comes loose in the rear while the front is a little stuck,SNAP!!!
Yes,SNAP!!!! AHHHHRRRG!.They are very weak where the hinge pin for the hinged floor plate is drilled.Not much harder to break than a pencil!!
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Old September 15, 2008, 09:59 AM   #6
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the earlier 8x57 was a larger dia and can cause pressure.
The original 1888 Commission rifles in 8X57 fired a .318" round nosed bullet ("J bullets"), replaced in the M98 with a .323" spitzer bullet ("JS bullets"). Although civilian versions still used the "J bullet" until WWII, M98 military rifles were chambered with the larger diameter bullet and most of the earlier rifles were rebarreled with the larger bore in 1905.
My issue is when I test fired the rifle it shot fine without and signs of stress on the action or barrel.
How would you know? It didn't blow up, obviously, but you have no way of knowing whether this stressed or damaged the action. Probably not, but you have no way of knowing it.
But when I go to open the bold it is very stiff and I have to literly slap it in order to bring the bolt upward.
Very typical signs of either high pressure or a poor attempt to smooth out the cocking cam surface. Find out what type of ammo you are shooting, and try dry-firing the gun and cocking the bolt (with the rifle empty). If the ammo is OK and the rifle cocks well, you may ahve some bolt lug issues, possibly a peened receiver.
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But what do I know?
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Old September 15, 2008, 04:25 PM   #7
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I appreciate this was your Dad's riflle. I admire you have this connection.I have Grandpa's Railroad watch.
A cool thing about a Mauser is ,even with all the different mfg's and variations,a Mark 10 bolt or commercial FN or a new Rem 798 bolt will likely be a drop in(pretty much for most other 98's) but we have no way to know all the history and variables.
Likely,it was a good 98 when he started.I bought 3 commercial bolts myself.A $60 bolt isn't a bad plan relative to welding,forging,shaping,etc.
Your ammo is one variable in his equation.Some surplus ammo is just out of spec.I have chronographed 2900 fps Portugese 7.62 Nato ammo.It might be handloads of an obsolete load data with modern powder(Old 4895 or 4831 data is way too hot with new mfg powder).You might try a box of Rem or Win or Fed new ammo.The first good plan might be to consult a good smith to just evaluate it.
It is going to work out.Be safe.
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Old September 15, 2008, 06:39 PM   #8
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I suspect your problem is an un-head spaced bolt.

Bolts DO NOT just "drop in" and really need to be professionally checked for proper head space.
A prime symptom of head space problems is sticky extraction.
Just cycling loaded rounds through will tell you almost nothing of any value about head space.

I recommend getting a gunsmith to check the head space with a set of precision head space gages.
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Old September 15, 2008, 08:03 PM   #9
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How is the bolt lift when you dry fire it, pulling the trigger on an empty chamber? Is it the same as after firing a live round off? Tom F.
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Old September 16, 2008, 03:03 AM   #10
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On the drop in bolt,I agree I did not say that well.A headspace check is necessary.I just meant it would go in.
Playing with a mix of commercial and military will all go together,maybe with some fitting.I intended to make the point this stuff has been made all over the world over many decades on many different machines,by many people and a mix of parts may take some fitting.I guess I lost my train of thought .
Once again,absolutely,get the headspace checked.
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Old September 16, 2008, 11:15 AM   #11
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Without inspecting the brass, it is hard to say what the issue is? If you have the rough chamber Harry suggested, you will probably see shiny spots on the case where it was dragged out against them. Often these show up as bright rings around the brass because the roughness is circular gouges created by improperly lubricated reamers being run in too quickly and without adequate chip wash-out. If you have high pressure, the fired cases will be difficult to put back into the chamber after firing but before resizing. The dry fire suggestion is good in case the problem is in the bolt as described earlier. Look for a crease at the case mouth in case the chamber neck is short. If your dad was working on it and it is a replacement barrel, he could have got a short chambered barrel that has never been finish reamed and therefore has no throat. That would make for some high pressure, though I should think you feel it when you inserted cartridges. In addition to having been made all around the world, these guns have been gunsmithed all around the world, often by amateurs looking for an inexpensive surplus gun to learn on. Having a qualified gunsmith inspect it might not be a bad plan?
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Old September 19, 2008, 09:01 AM   #12
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michiganmauser - As Dferriswheel posted above - Please get the headspace professionally checked before shooting it any more !

Just because rounds may chamber, and even fire, doesn't mean a rifle doesn't have dangerous excessive headspace.

In a "worst case" scenerio, it's possible that a casehead could let go, catastrophically disassembling the rifle in a shooter's hands & gassing/shrapnelling the shooter's eyes.

The original headspace was set, with the original bolt in place, by finish reaming the chamber to the proper depth as measured by go/nogo headspace gauges - and when the bolt's replaced, headspace most likely changes along with the bolt. All bolts are not created equal.


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Old September 19, 2008, 09:58 AM   #13
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I should have included the possibility of firing the 8 mm in a Mauser that had been rebarreled and chambered for .30-06, which I believe was blamed for 4 of the sixty-some Springfield receiver failures that Hatcher investigated. So not only should the headspace be checked, but before that double-check the chambering and bore dimensions.
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Old September 28, 2008, 06:51 PM   #14
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I have built plenty of Mausers.
I have overloaded plenty of Mausers until the bolt had to be pounded open.

I can see three possibilities:
1) The receiver lugs have set back, so the bolt lugs are in a hole after firing. The brass lengthens and traps the bolt lugs. The bolt lift does the work of pushing the shoulder back on the brass.
2) The chamber is horribly misshapen.
3) The ammo is way overloaded. Mauser case heads can be rated from 35k [8mm] to 65k [270], but they all have the same strength: 62kpsi for long life. If the handloaded ammo is ~75kpsi, the bolt will be hard to lift.

Notice how none of the possibilities were caused by the bolt?

1) If you could come over to my house, the Mauser junk yard, we could pull the barrel and measure the distance from the large ring to the bolt face as we open the bolt. It should be a monotonically increasing function [ever take calculus?]. If not it is the receiver.

2If the receiver is bad, we have to lap out the lugs.
If it is good, we need to check the chamber.
We can do a concentricity check on the fired brass or a concentricity check on a Cero Safe casting impression of the chamber.

3) If the handloads are too hot, the primer pockets will allow for very easy insertion of the next primer.
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