m48 mauser bolt wont close on round

Status
Not open for further replies.
7

701

Member
Joined
Oct 9, 2006
Messages
34
Hello out there
I recently got a Yugo m48 8mm master and am having some trouble. I cannot quite close the bolt on a shell. It comes within a mm or so it seems from being able to chamber and close the bolt downward but just won't quite make it. I took it to a local shop, they tell me it is in fact 8x57 as it is marked (Cai) and the headache is correct. They put a straight (non bent) bolt from another Yugo(24/27 I believe is the model?) And were able to fire the rifle with that bolt. They were also able to chamber and fire the other rifle using my bolt, but my bolt will not chamber in my rifle. Both bolts looked identical in length etc. Aside from my bolt being bent with the flat underside on the ball, theirs being a complete sphere. We did not take a micronometer to the bolts, but did look at them carefully to see matching lengths etc. Does anyone out there have any ideas or suggestions? The shop offered to swap bolts but I didn't want to start mixing and matching parts until I learned more about this as I would prefer to keep it matching. ( the way I received it at least.) Thank you for your help and thoughts!
 
the headache is correct.
Click to expand...

Your rifle should have been checked using head-space gauges. If if does snot head-space correctly then you need to find a bolt that will.
If it head-spaces correctly using the gauges, then it is simply bad ammo or hardened cosmoline in your chamber.
 
Awesome. I will pursue further chamber cleaning. They used their ammo, which was old surplus. I purchases some of the same ammo from them a couple weeks ago and had the same problem. I have tried that, plus privi plus wolf all with the same results. If it is a cosmo issue, would it still be possible to fire with that other bolt in it? It cited fine with theirs, just not mine. My chamber is currently taking an overnight bath, as is the assembled bolt. Thanks for the help! Will get back with any results I have.
 
1. Does the serial number on your bolt match the serial number on the receiver?

2. Did you clean the lug recesses in the receiver?

3. Did you visually inspect the chamber looking for dirt, debris especially in the shoulder area of the chamber.

4. Military rifles have "longer" headspace than commercial rifles and chambering a round with a matching number rifle should not be a problem.

5. The 24/47 Mauser is a control feed and the cartridge must be fed from the magazine and slip between the bolt face and the claw extractor

The chamber can be cleaned and polished with a shotgun cleaning mop, J&B bore paste and Kroil using a battery drill.

The 5th rifle back is a Yugo 24/47 and all these rifles have matching numbers and they "ALL" have plenty of excess headspace and will chamber any ammunition. (Like parking a VW Beetle in a blimp hangar) :rolleyes:

IMGP6390.gif
 
What biged said:

Are you feeding from the magazine, or just dropping the round in the chamber?

You must feed from the mag so the extractor can slip over the rim of the cartridge.
 
This is an 8mm Mauser that I refinished, which included welding the bolt on in the downward position.
2005_gunsmithing_project.jpg
When the bolt was repositioned, it disturbed the positioning of the bolt stem against its mating surface on the receiver. If it isn't positioned just right, (that is turned a full 90 degrees), the safety will not work and the rifle will not fire. It thinks it's out of battery, which it is.

Look carefully at the mating surface where the bolt stem touches the receiver. With a bent-down bolt it is touching the receiver with less rotation than when the bolt was straight. You must make a light file cut in that spot to allow the bolt handle to drop down far enough for the bolt to turn a full 90 degrees.

Locate a riflesmithing book that covers refinishing a Mauser. It will explain in better detail than me the proper process for making sure the bolt is closing properly with the safety engaging.
Good luck,
Michael
 
So, thank you all for your input and help! I just heard back from the gunsmith, who checked it out by cast etc, and apparently this rifle was teamed out to a (an) 8mmx60, which I Wikipedia'd and its an obscure hunting round popular where military clambering are illegal for civilian use. I suppose it was a wonderful round, and somewhat popular in the far corners of the earth many years ago. Guess it doesn't do me any good now though. Currently deciding whether to take the cheap route and replace it w a proper 8mm barrel, or go the fun and more expensive route, and have the smith "scout" it in 30.06, which surprisingly didn't seem too horribly expensive all things considered and mainly due to me not having any $ in the gun from the start. Kicking around the idea of a short (16.5-20) inch barrel, irons, and a shortened stock ( I'm a small guy) , drilled for a forward mount scope ( though that'll go on much later) , in 30.06 was the recommendation. Not in a rush, as ill have to sell my 8x57 dies and the ammo I bought for it before I discovered the chamber issue, etc. And save up the cash to do it. Anyone have any thoughts, criticisms or suggestions as to this course of action? Thanks again!
 
You have many choices, including chambering the gun to 8mmX63 -- which is also called the 8mm-06. Just run a .30-06 reamer into the chamber, and you can use .30-06 brass necked up to 8mm.

This was a common modification after WWI and again after WWII, when a lot of GIs brought back 8X57 Mausers and couldn't get ammo for them.
 
98 Mausers are one of the easiest rifles to rebarrel. You could also pick up a surplus 8x57 barrel cheap. You could also have it rechambered for the 8mm/06 which is pretty much the equivalent of the 338/06. Any local gunsmith should be able to do any of these modifications for a relatively small sum of money.
 
701, I can not relate, going backwards, the 8mm60S will not chamber in an 8mm57, the 8mm60 is longer .127 longer than the 8mm57 in length, the shoulder of the 8mm60 is forward of the 8mm57 by .071 thousands, meaning the 8mm57 will chamber in a 8mm60 with room to spare.

Going back to the beginning, they changed bolts and fired your rifle with an 8mm57 round, after ejecting the case they, the smith, had no clue as to the effect the chamber had on the fired case?? To me that is mindless, I determine the length of the chamber from the bolt face to the shoulder of the chamber first, and I am not a fan of head space gages, had the smith used one or all three gages, the go, the no and the beyond, he would have found all three gages would chamber (with room to spare, and I ask "Then what" Anyhow, I make gages from .017 shorter than a go gage to infinity, or I modify a GO-GAGE to measure chambers that are from go gage length to infinity.

And I do not understand the smiths difficulty understanding the relation between a round chambering and a bolt not closing, I have been at different ranges when a bolt locked up, it would not open, close or rotate, the Mauser is a control feed, meaning it is designed to feed ammo from the magazine, treating the Mauser like a push feed can create problems with bolt closing, not something that can be explained in a manner that would even create curiosity but the Mauser requires less understanding on the part of the smith and especially the reloader when firing an 8mm57 in an 8mm60S chamber, still, the shoulder on the 8mm57 case was blown out .071 thousands and then the smith HAD TO DO A CHAMBER CASTING?

Again, I determine the length of the chamber first, I determine the effect the chamber will have on the case when fired, again, I have a M1917 with .016 thousands head space, not a problem, the rifle has had .016 thousands head space from the beginning, my best source for 30/06 cases with an additional .016 thousands added between the head of the case and it's shoulder is the 280 Remington case, it has an additional .051 thousands added between the head of the case and it's shoulder, (JIC) just in case I do not want to fire a case to form, again I am a big fan of forming first then fire, after firing I get once fired cases, others get fire formed cases after firing, I save one firing and I know where I want the shoulder.

30/06 cases would be a good resource for 8mm60 cases, an 8mm57 full length sizer die would be a good die to use when forming 30/06 cases to 8mm60, I am a big fan of forming dies, BUT, the general consensus of this forum will say "it can not be done" and? I say it can be done BUT the reloader must know what they are doing.

The shoulder of the 30/06 is ahead of the 8mm60 shoulder .051 thousands, my opinion, for the relaoder that knows what they are doing!!! IT IS A CAN NOT MISS THING, and the 30/06 case is longer by .132 thousands. and again, I use a hack saw then finish with a file.

F. Guffey
 
The rifle was fired by the mauser "expert" at a different shop than the one that did the casting etc. He did not examine the brass afterward, and I was unfortunately too dumbfounded that he had dropped a different bolt into it to think to take the brass with me I'm embarrassed to say. The second smith who did the casting etc. Also fired it once ( not sure how as I couldn't get it to chamber, but he had also mentioned that he got in there and really cleaned up the insides so perhaps that allowed it to close on the round, he fired 1 shot and explained that the shell formed quite a lot and that the neck was where he saw there was a change, I believe this is when he cast it to discover the 8x60. That's all I know on that one, but regardless, it seems 8x60 is the clambering. I appreciate the info on reading and the -8
08 suggestion. Unfortunately, I am rather new to the reading game and am a bit too hesitant to try that level of expertise yet. ( only working w 357 now, still inside the 500 reload mark) thank you again for all of the information! My favorite thing on this forum is learning something new, and also seeing how much there is out there to learn!
 
http://www.rcbs.com/downloads/2010_SpecialOrder.pdf

Part #56379 is a group G die cost $143.95 from RCBS, less when ordered from MIDWAYUSA or other sources.

Point? When considering other options as changing the barrel, chambering to 8mm/06 and the expense with parts and labor consider purchasing the dies. RATIONAL: Years ago I purchased forming dies for most of what I shoot and reload for, cases will never cost me more than .10 each if I can form cases from 30/06 cases. New formed store purchased cases cost .35 cents plus, after forming 100 cases the forming die is paid for and I find forming dies can be used to form cases I do not have forming dies for, if I had one forming die it would be the 308 W, again to make it work, the reloader must know what they are doing, as in doing instead of talking about it, and my favorite chamber reamer is the 25/06 Ackley Improved.

The link at the top is a must have...for me... When talking to RCBS ask for a free Special Order Catalog, there are times a forming die is not necessary.

1 800 533 5000

F. Guffey
 
Status
Not open for further replies.

Similar threads

H
  • Locked
Yugo M48 Replacement Bolt?
Replies
2
Views
818
yodar
Y
K
  • Locked
Problem with Mauser bolt
Replies
7
Views
723
kestak
K
G
  • Locked
Place to purchase bolt for M48 mauser?
Replies
4
Views
1K
mustanger98
M
A
  • Locked
Yugo Mauser Questions
Replies
5
Views
1K
Jim K
J
Random 8
  • Locked
Interesting Mauser 48
2
Replies
40
Views
1K
Dave DeLaurant
Dave DeLaurant
Back
Top