Mauser 98 Custom Rifle - Stiff bolt

D

davery25

New member
Hi guys,

I have a custom 'mauser 98' (a rifle built from bits and pieces) in 22-250. It's been checked for headspace but after the first 2-3 shots the bolt gets very hard to lift once fired. If i leave it for a while, its good for another 2-3 and then the bolt becomes stiff once the rifle heats up again.

Any idea what could cause this? It doesnt really to be a dangerous issue - just an annoying one.
 
bits and pieces makes it kind of difficult to say. There is more involved than just correct headspace. The fit of the locking lugs in their recesses, for one.

It is possible that either the bolt, or the reciever is a touch "soft", or its possible your loads are too warm.

It sounds like you are getting increased bolt thrust, for some reason, setting the lugs back hard enough to make things sticky. Or it might be something else entirely.

Sorry this isn't much help, but without the rifle (and fired cases) to examime, its all just a "shot in the dark".
 
well if nothing else i enjoyed the pun. thanks 44AMP.

The loads fired were:

20x federal powershok 55grn
20x highland 55grn
20x Remington core-lokt 55grn

All standard factory ammo and all produced the same result so it cant be the ammo.

Strangely though it seems only to occur when the rifles fired a few shots.

I should clarify - the barrel and receiver is an FN and the bolt came from a Mauser 98.

What would cause this increase bolt thrust if that's the issue?
 
Residual oil in the chamber will increase bolt thrust.
Is the barrel being cleaned any time during these sequences?
Have you cleaned the bolt recesses and lubed the bolt lugs slightly?
Do the fired cases have rub spots on the head like the bolt face was "scrubbing" against it?
Are there pits on the boltface around the firing pin hole?
It's possible the bolt lugs aren't bearing equally in the recesses and firing multiple rounds is causing some increased drag or galling on the lug taking all the load.
 
Sounds like you have a case of "Locking Lug Set Back".
Here it is described in a Mauser 98 in the book "Bolt Action Rifles" By Frank De Haas, Wayne Zwoll.

"After each firing, if the bolt handle can only be raised with difficulty, this may indicate locking lug set back in the receiver ring. This is usually a sign that the receiver is very soft, and the locking lugs have hammered depressions into the locking shoulders. The result is that when the bolt is opened the locking lugs must pass from the depressions to the higher undamaged part of the locking shoulders, forcing the bolt forward in so doing. The total set back may only be a couple of thousandths of an inch, but even so on opening the bolt the fired cartridge must be forced forward into the chamber the same amount. Such a receiver should not be reused. This condition is not easily corrected and it indicates, possibly a very soft receiver".
 
Inspect the inside of your lug recess area, if the upper one has a shiny vertical line it is from the reciever being "mushed" into the ejector split. It is a sign of a soft receiver.

If however you just have a tight chamber that is heating up and making things tight, it should go away with time as you wear in the rifle. I seldom hear of a soft FN action, some Santa Barbaras yes, but not FN.

Jimro
 
Thanks for the help guys. I'll check out the lug recess - does this mean unscrewing the barrel though?

Also, assuming that is the soft receiver issue - is this a danger issue or am i fine to keep using it. Being a 22-250 that i fire fairly rapidly i assume the barrel isnt going to last that long. can i just change (or harden??) the receiver once i take it in for a barrel change.

After this barrel ill likely rechamber it in 8mm mauser or 30-06 so that will solve that issue (receiver will have to be changed) but im now concerned about a danger issue.
 
mobuck - no the barrel doesnt get cleaned during firing - i've not owned the gun for long (I've fired 80 rnds all up so far) but i generally clean after every 60 - 80 rounds. Also the gun is cleaned after firing every time without fail, and heavy viscosity 'burrsthreo' storage oil is used while in the safe.

Until i began plugging all my barrels with tissues so stop oil drainback - oil would always leak back into and all over the bolt face as well so there could be oil in the recesses even though the bolts are closed in the safe and the rifle uncocked.

Is there a better method of storage? i dont like removing the bolts as it means that the bolts are cocked for the 2-4 months between firings.
 
My experience with "set back recess syndrome" is that it will occur with every shot rather than starting to be noticeable on shot 3,4, or5. It would seem to be related to heat or fouling buildup but the rifle hasn't been cleaned so the fouling is there for each shot. Possibly a very tight chamber?
I'm grasping at straws so hope one of the other answers helps.
 
Could be that the heavy viscosity storage oil thins out a little after getting heated by a few shots, or some that has migrated into the action during storage gets onto your cartridges after a few shots. That would be my guess. Take it apart and degrease it, your problem may go away. Gets into bolt while upright, then leaks onto catridges in magazine while horizontal. That would take enough time for a few shots before you were putting an oiled cartridge into the chamber.
 
Another thing to check is bolt lug engagement. Paint the back surface of all three bolt lugs with a permanent black marker. Work the bolt once and see what comes off. The back of the third safety lug should show no contact, and the front two lugs should show relatively even contact.

Jimro
 
ahhh cripes...i tried to take the rifle apart on the weekend except i couldnt get the action screws loosened. i can only conclude that the rifle is glass bedded and whoever did it didn't use any or enough release agent and now the thing is stuck together. I've scraped the screw on a very expensive custom mauser - won't be trying that again.

At the risk of being asked to create another thread...does anyone know how i can loosen the screws and remove the action? brute force doesnt seem to work:rolleyes:
 
Forster makes nice replacement screws,but,slow down.Sorta stuck is time to drink coffee,ponder,and not break things!Example,pulling out on the trigger guard to get the guard assy out...Ahead of the mag box is that boss the front guard screw goes through?Its only coming out straight,but pulling on the guard doesn't do that.I broke an aluminum assy that way,on a Husquvarna.Where the hinged floorplate pin goes through.Snap!If/when you are successful,make sure there is nothing bearing on the sides of the guard screws.Clearance! It will shoot better.
Stuck screws may indicate a not so good glass job.It can happen that tightening the screws on the rifle while glass bedding will distort the action.That might mean,since the bolt is straight,you have lost some clearance.3 or 4 rds might make enough heat to change from line to line clearance,to some bind.
This gun stuff gets real educational some times.You might have bedding compound in the locking lug recesses,etc.
Then,I sort of wonder,if a guy had an FN receiver...with an FN bolt,how many reasons are there to replace the commercial bolt with a military?They are valuable together,apart,not so much,unless something went wrong?An FN receiver is likely real good,but,if something happened to hurt the bolt?
On the impact driver,I dunno,maybe,but seems like epoxy can take a jolt,but slow steady pressure will give resin time to move.
If you think your friendly local gunsmith will be involved,I would say,less is more.You really do not want anything to go "wronger"before you give it to him.
 
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HiBC that was all useful suggestions - thank you. but now, breaking news from the world of the custom 98

I neck sized the aforementioned fireformed brass and as usual - inserted a bullet into an unprimed case to be used as a template to seat bullets with (i seat to the lands and then back off a little) except when i inserted the case and bullet the bolt would not close!

i tried pushing the bullet and case out from the muzzle end with my cleaning rod but it was all firmly jammed in. I had to resort to smacking the bolt down to get it to close and hence have the extractor grip the case to remove it.

THis tells me one this - the chamber is indeed very VERY tight. A gunsmith inspected it prior to picking up the rifle from the shop when i bought it and they said the rifle was safe.

Its looking like the chamber is SO tight that i cannot even use fireformed brass - i'll HAVE to FL size all brass.

im thinking that this is undoubtedly the casue of the stiff bolt lift but I'd like everyones opinions on this.

Is a chamber this tight dangerous?
 
alright, now im thoroughly confused. i just full length sized a case and it was still hard to put the bolt down. A hell of a lot easier than with the neck sized brass but still hard.
 
First off, I would say you are way over oiling your rifle if it is running all over the place while just sitting in a cabinet. A very light film of Break Free will protect it completely unless you are in a VERY humid environment.

I would try to find a competent gunsmith who can do a cerrosafe chamber cast of your rifle to see just what the problem is. Sounds like it's way too tight.
 
thanks black mamba. do you know if chambers can be loosened or 'opened up' a bit. surprisingly - this ultra tight chamber gives the same sort of accuracy as my standard hunting chamber in my Howa M1500.
 
do you know if chambers can be loosened or 'opened up' a bit
Click to expand...

A gunsmith/riflemaker with the proper chambering reamer could cut it a little deeper if that is in fact the problem. As the case/chamber has some taper from head to shoulder, deepening it would make it slightly wider as well.

Even though the chamber is tight, that could hurt accuracy especially in the neck area. Impeding neck expansion upon firing could release the bullet with pressure on one side, causing it to enter the lands "crooked" which would upset accuracy.
 
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