mauser bolt hardness on open

hallo ,

i bought recently a nice Persian Mauser 98/29

during tests at the range i noticed that after each fire the bolt
was considerably "hard" to open ( by a hand but with a good effort )

.....only on open ......and without traces of overpressure ( the load
was about 44 gr of Vhita N140 under a Sierra MK HPBT 200 gr )

well, i do not know , the possible reason of it - i know this bolt load
the spring of the firing pin on open and the spring it is hard

....may be the shoulders of the receiver worn ? so on open the bolt
could have to pull forward the case

please some "Mauser spcialist" can help me ?

thank you in advance for some opinion

CC

.....not "pull" , but "push" forward

sorry

Quote:

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Originally Posted by CCAMERA50

( the load was about 44 gr of Vhita N140 under a Sierra MK HPBT 200 gr )

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That is well within the range (42.7 - 47.5 of N140) published in the Vihtavuori reloading manual for the 8x57IS with a 200gn bullet. So one would not expect any overpressure or signs thereof.

Take a very close look at the case when it is extracted. Can you see any bright marks or bumps? There may be damage to the chamber in the form of rings or rust pits. When a cartridge is fired, the case expands to fill all these recesses, and if the rings or pits are deeper than about 0.002" the case will be hard to extract.

WARNING !!! If your chamber has such a defect, do NOT try to make a chamber cast - it will be impossible to extract!

Quote:

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Originally Posted by Patrick Chadwick

That is well within the range (42.7 - 47.5 of N140) published in the Vihtavuori reloading manual for the 8x57IS with a 200gn bullet. So one would not expect any overpressure or signs thereof.

Take a very close look at the case when it is extracted. Can you see any bright marks or bumps? There may be damage to the chamber in the form of rings or rust pits. When a cartridge is fired, the case expands to fill all these recesses, and if the rings or pits are deeper than about 0.002" the case will be hard to extract.

WARNING !!! If your chamber has such a defect, do NOT try to make a chamber cast - it will be impossible to extract!

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Thank you Patrick ,

Usually , the first time i shoot a new gun , i make a close case inspection ( it the first step of a
personal standard procedure at the range - ....after inspection and cleaning and slugging at home)
well.....i saw nothing remarkable -

i inspected the bolt lugs but ....nothing remakable
i also ( after it ) stripped the whole bolt and tested it for some kind of tolerance wehn closed
( without spring , firing pin , and all the parts on the rear ) - nothing doing

....i do not know waht to think again ....a inspection of the lug recessees by a borescope ?

I have a Mosin Nagant that I had to shim the rear action screw because without it when tightened I guess the receiver flexed just enough to bind the lugs. Just cycling the bolt I could feel slight resistance but after firing I had to beat it open. All good now....

@ WarPig1976 ................................
me also - on my K31 scissors and Coke aluminium tin work better than ...the better GP11 crtg
unfortunately in this case it do not help - i tested immediately your theory ......nothing
.................................................. ....

i think remain me only to try to test ( like just told me a friend ) the gun with another bolt from another similar Mauser
...if the problem there is still / or not , that could indicate where "go to looking"
the shoulders or the bolt : - || correct ?

a opinion ?

.....none ?? :banghead:

Two easy checks come to mind. I'm sure you have already, but make sure there's no Cosmoline or otherwise gunk hiding in the receiver and #2 make sure you have the proper spring in the bolt. That exhausts my layman trouble shooting skills.

Quote:

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Originally Posted by WarPig1976

Two easy checks come to mind. I'm sure you have already, but make sure there's no Cosmoline or otherwise gunk hiding in the receiver and #2 make sure you have the proper spring in the bolt. That exhausts my layman trouble shooting skills.

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Hi ,

first , thank you for opinion

...all the cosmoline elimination it is the first operation i make when a gun come into my hom
...the firing pin spring , it seem to be jus his own , ( ...effectively too "hard" ) however to
"improve" the trigger ...shoot ( correct word ? ) i made a softer spring to test tomorrow
when i will go again to the range for test again

....even renting the K98K range property to see differences also trying a bolt exchange

....continue to the next episode :)

CC

Ok, so there have been modifications to the bolt. We'll be here for an update....

Quote:

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Originally Posted by CCAMERA50

Hi ,

first , thank you for opinion

...all the cosmoline elimination it is the first operation i make when a gun come into my hom
...the firing pin spring , it seem to be jus his own , ( ...effectively too "hard" ) however to
"improve" the trigger ...shoot ( correct word ? ) i made a softer spring to test tomorrow
when i will go again to the range for test again

....even renting the K98K range property to see differences also trying a bolt exchange

....continue to the next episode :)

CC

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.....Range close for maintenance works - re-open the next week

aaaghhh !! :crying: .....grrrrrrrrrrr :bitch::banghead:

Quote:

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Originally Posted by WarPig1976

I have a Mosin Nagant that I had to shim the rear action screw because without it when tightened I guess the receiver flexed just enough to bind the lugs. Just cycling the bolt I could feel slight resistance but after firing I had to beat it open. All good now....

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This describes a Finn Model 91 I have pefectly. How much shim did you have to use to correct this?

Normal cycling no problem but, fire it and you have to use a mallet to open it.

I have cleaned the chamber and even made a crocus cloth polisher and ploished the chamber. No luck. I will try the shim up.

Thanks.

Al

To be honest I didn't measure. I just thinned a washer I had in my "you never know" nuts,bolts,washers bin until I felt no resistance. Also, I used cork gasket material to keep somewhat good receiver/stock contact cut to fit around the washer.

It's a bubba job but it's a range rifle and reversible...

Thank you and, at the risk off hijacking the thread, I did a similar shim to the action mounting screw on my M1969 Romanian .22 because the screw was bottoming out before it could snug the receiver to the stock. An unexpected result was that the rifle fed 90% better from the magazine after I installed the shim.

(Backing out of CCAMERA50's thread.)

Al

Hi guys !

finally i tested the first changes :

- firing pin spring replaced by another more "human"
- thread of the rear block bolt lubed with copper grease ( and helicoidal "rail" also )

now the required force to open after firing it is "normal" ( with the same crtgs loads then before )
and consequently even the trigger required force it is fallen to 1,7 kg = 3,7 lbs
the percussion it is still excellent - the result on target at 100 mt ( open sight ) it is 5 shots into an inch

....really a"tack driver" :dancingbanana::dancingbanana::dancingbanana:

however i wouldlike still study/"go around" the helicoidal size of the hammer and also test the bolt exchange

...i will tell you again

regards

CC

Looks like you solved your problem... I think....:thup:

Quote:

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Originally Posted by WarPig1976

Looks like you solved your problem... I think....:thup:

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i ...hope / trust

....reasonably it seem it was a bolt problem

but ....let me see and test again

surely i will say you something more about it

regards

CC




i will look about again

Hi guys ,

yesterday i gone to the range with the Persian for the last tests
.....before to put it to the foundry

i made :

- an accurate cleaning ( shining ! ) of the rear of the bolt tube ( where is the helicoidal
ail ) by a good bodyshop polish
- an accurate cleaning ( by the same method ) of the receiver rails
- an accurate greasing by copper grease of the rear bolt tube internal thread , and
also of the helicoidal rails and firing pin and f.p.spring
- the springs was already changed by a set of more soft springs

well ! finally a perfect , velvety handling before and after each shoot :dancingbanana:
....and it shoot very well also ( three holes in an inches at 100 yards by open sight ):super:

really .....a "happy end" :cheers:

Thanks at all !

regards

CC

Sweet is the taste of victory, Good job!!