Indexing barrel on a Mauser

[Deep Six]

I recently picked up a Yugo 24/47. I didn't notice it at the time, but the sights (both front and rear) are pointed to about 12:30 when you look down the barrel from the breech. The sights do have the locating screws installed so they're where the factory put them. The goofy yugo extractor cut in the chamber end of the barrel (not present on other Mauser 98s) is also correctly aligned with the extractor groove in the receiver. So it seems that everything is put together correctly and has not been moved in its 70+ year life. It just seems strange that the factory would put the sights at 12:30 instead of 12:00. I have a hard time believing tolerances were this big...

Anyways, this is annoying when looking down the sights and is causing windage to be off. I've corrected it for my 50 yard zero by adjusting the front sight but it still bothers me. I believe I have 4 options:

1. Live with it (it's just a plinker anyways)
2. Index the sights to 12:00 and re-solder
3. Index the barrel in the receiver. I pretty sure this will require re-cutting the extractor notch which would probably require setting the barrel back, which will screw up the fit of the stepped barrel profile in the stock. This will probably make headspace go out of spec.
4. Drill and tap for scope mounts and forget about the sights.

Due to my perfectionist tendancies with guns, I don't like option 1. Option 4 would be easy (I have the drilling jig) but I loose the historical value/feel of the rifle. Option 3 is a mess with all sorts of consequences. Option 2 would be relatively simple, but I've never done high-temp soldering before and don't really know where to begin with it. I'd actually be a lot more comfortable doing a couple tack welds with my MIG setup to hold the sights in place but everyone says thats a terrible idea. There are no gunsmiths I'd trust in the area and I don't want the hassel or expense of shipping it off.

What to do?

[str8shot426]

I would open the extractor groove enough to turn it in that little bit. It sounds very slight.

[Mooseman]

Are you saying the barrel is "underclocked" with the term 12:30 position ? If so , the barrel would need to be removed and the face and shoulder could be stoned a very slight amount (.001-.002) and then it may need a small amount of metal removed from the extractor slot , but usually they had lots of clearance. Then retorque the barrel to index. I have never seen a Military Mauser that had close headspace that you would have to worry much about if it is tightened 1-2 thousandths since they were pretty generous with battle rifles headspacing.
If you dont have the tools , then I suggest sending it to a qualified Gunsmith Like Steve Bowers (Sbowers on this forum) who specializes in Mausers, and having the work done.
Rich

[fguffey]

Your barrel came off of another rifle. The index of 12:30 would indicate the barrel is off by .0035" (using fast ,math) if the sight is leaning to the same side the bolt is on.

What does that mean, move the barrel back by cutting the barrel seating surface on the face and at the end of the barrel shank threads.

Remember, moving the barrel back reduces the length of the chamber from the shoulder to the bolt face.

If the sights are leaning to the left side of the rifles, backing the barrel will increase the length of the chamber from the shoulder to the bolt face and the real bad news, backing the barrel out will loosen the barrel.

Soldering, heat, depends on what is used as a solder, straight lead would be 650 degree.

F. Guffey

[Deep Six]

Your barrel came off of another rifle. The index of 12:30 would indicate the barrel is off by .0035" (using fast ,math) if the sight is leaning to the same side the bolt is on.

What does that mean, move the barrel back by cutting the barrel seating surface on the face and at the end of the barrel shank threads.

Remember, moving the barrel back reduces the length of the chamber from the shoulder to the bolt face.

If the sights are leaning to the left side of the rifles, backing the barrel will increase the length of the chamber from the shoulder to the bolt face and the real bad news, backing the barrel out will loosen the barrel.

Soldering, heat, depends on what is used as a solder, straight lead would be 650 degree.

F. Guffey

I had reached the same conclusion as you - that the barrel is off a different rifle. I did try to unscrew the barrel last night but my barrel clamp wasn't up to the task (it's worked fine on commercial actions in the past but these old war guns are really in there tight!). I think I will build a better clamp and try again.

The sights are leaning to the bolt side of the gun - the barrel needs to be tightened a smidge. If your math is correct and it will only result in a set back of 3.5 thousandths, I suspect headspace will be OK. I'm tempted to try stoning that 0.0035 off the face of the action and face of the barrel. I don't have a lathe to do it and would be using hand tools - do you think I can keep things square for 0.0035"?

Like the other guy said, these battle rifles usually had pretty generous headspace and 0.0035" probably won't be an issue. If it does throw headspace out of spec a reamer rental isn't a big deal to deepen back to spec.

[Mooseman]

I venture to say .0035 will be way too much from my experience torquing barrels and fitting.
Rich

[Deep Six]

I venture to say .0035 will be way too much from my experience torquing barrels and fitting.
Rich

Way too much what? Way too much tightening without relieving the face and shoulder?

[FrankG]

I agree with Mooseman. I think it you were to just remove barrel clean threads in receiver and barrel shank, lube with a little anti seize and retighten to 12:00 with a bit more force.

[Mooseman]

Just a light stoning and removing .001 will give you more index combined with torque...Im saying creep up on it , and dont remove too much metal . The math says .001 will give 4.337 degrees at .01309 per degree so you get .0567 more rotation not including torque !

[John Taylor]

I have found many times the barrel can be torqued up more if you work it back and forth a few time, tighten and loosen. Oil the threads and face of the action. Each time you tighten it the barrel will turn a bit further. I do the same thing on new barrels to make sure there is good thread contact.

[Deep Six]

Thanks for the replies all! I just got home with some materials to build a stronger barrel clamp. Hopefully I'll have the barrel off this evening yet.

[largom]

I have found many times the barrel can be torqued up more if you work it back and forth a few time, tighten and loosen. Oil the threads and face of the action. Each time you tighten it the barrel will turn a bit further. I do the same thing on new barrels to make sure there is good thread contact.

John T. has the right answer. I would do that first before I removed any metal.

Larry

[Deep Six]

OK. New barrel clamp works good. No luck getting the barrel off though. Thus far in my hobby, a 15" pipe wrench with padded jaws has sufficed as an action wrench. This time I reached the limit of how much torque I can apply with the 15" wrench and it wouldn't budge. I work on old rusty trucks a lot and I definitely know how to crank on a wrench. I had to stand on the work bench the barrel clamp was mounted on to keep it on the ground. I probably had close to 200 ft-lbs on the stupid thing and it just wouldn't budge. I thought about adding a cheater bar to the wrench but figured any more torque and something was going to snap.

Did they use red Loctite putting these things together or something? Would heating the threaded portion of the receiver help?

[country gent]

I dont believe they used anything on the threads, so many years of set up and of rust pressure setting going on. Soak the seam and joint in the reciever with kroil several days. then lightly heat. A few blows from a mallet on the wrench may help to pop it loose also. Be carefull with the heat. Appling force to the wrench while a buddy taps the handle with a mallet will give a "shock" to it and may get it loose. Check to be sure no screws or other parts are locking it in place also. I once seen filler screws into the barrel shank/threads of a rifle. They acted like a key locking everything together.

[fguffey]

John T. has the right answer. I would do that first before I removed any metal.

Larry

I will disagree, it is most difficult to get two pieces .0035" closer together after they make contact, it is possible to pull the threads and worst, twist one or both the receiver and or barrel. and then there is the 15" wrench. The pipe wrench gains leverage by crushing.

There is no shortage of wrenches around here, I have 4 48" pipe wrenches, I will not use a pipe wrench on an action or barrel, I have barrels I purchased that were removed with pipe wrenches. One barrel was removed from a M1917 Eddystone. The smith said it required 3 people to remove the barrel, he qualified that statement by saying they could have used 4 but there was not enough room for the 4th. I chambered the 30/06 to 308 Norma and then installed in on a P14, complete with the Red and White stripes around the stock and receiver.

F. Guffey

[fguffey]

Way too much what? Way too much tightening without relieving the face and shoulder?

Yes, then there is stock removal and time. I would not do it but if you decide to screw the barrel in and out etc. etc. etc. add lapping compound to the oil, keep the laping compound off of the threads and out of the chamber, and remember, the front receiver ring and shoulder at the end of the threads. I check for contact between the receiver ring and shoulder on the barrel shank, I use a feeler gage. Not likely but possible the receiver is contacting the shoulder in the barrel without the face of the receiver contacting the 'C' ring. When you get the barrel off, check.

Fast math, the Mauser has 12 threads per inch, that makes it .08333" per thread. I would suggest you back the barrel out 1 turn until the sight was aligned, then I would measure the gap between the receiver and barrel shoulder, the gap will be less than .08333, how much less? The difference between .08333 and the actual gap will indicate how much metal should be removed.

+++ Plus the crush fit. I would be happy with .0015.

F. Guffey

[Deep Six]

Thanks for the tips. I did manage to stop by the store after work and pick up some stuff to make an action wrench. My idea is to use an exhaust clamp u-bolt and piece of 1/4" x 1" steel flat to form a cage around the action. Then I will weld half a 1/2" pipe coupling to the flat and screw in a 24" piece of pipe for a leverage arm. All because I'm too cheap to spend the $60 bucks Midway wants for the real thing. I'd go out to the barn and get it welded up but I caught a downright awful cold and don't feel like getting off the couch this evening.

[John Taylor]

A good barrel vice and action wrench are a must. My barrel vice has a 20 ton jack and I machine aluminum blocks to have a close fit on the barrel. The action wrench shown is one that will work on most old bolt guns and many other things. The one I use most often on Mousers fits in the rails and I have an 8 pound hammer next to the vice for stubborn barrels. Sometimes a little heat will work wonders, just don't heat it till it turns blue. I specialize in barrel work and R&R barrels almost every day.103165

[phaessler]

I know sights are the concern here , but no mention of headspacing? Regardless if the extractor groove lines up and the sights are off, if this is wrong then alignment might be for nothing. Just my thought.

[fguffey]

I know sights are the concern here , but no mention of headspacing? Regardless if the extractor groove lines up and the sights are off, if this is wrong then alignment might be for nothing. Just my thought.



04-23-2014, 11:15 AM
fguffey

Your barrel came off of another rifle. The index of 12:30 would indicate the barrel is off by .0035" (using fast ,math) if the sight is leaning to the same side the bolt is on.

What does that mean, move the barrel back by cutting the barrel seating surface on the face and at the end of the barrel shank threads.

Remember, moving the barrel back reduces the length of the chamber from the shoulder to the bolt face.

If the sights are leaning to the left side of the rifles, backing the barrel will increase the length of the chamber from the shoulder to the bolt face and the real bad news, backing the barrel out will loosen the barrel.

Soldering, heat, depends on what is used as a solder, straight lead would be 650 degree.

F. Guffey

In a world where everything is labeled 'head space' I make an attempt to distinguish the length of the chamber from the shoulder to the bolt face and the length of the case from the shoulder to the head of the case.

F. Guffey

[Wayne Smith]

Thanks for the tips. I did manage to stop by the store after work and pick up some stuff to make an action wrench. My idea is to use an exhaust clamp u-bolt and piece of 1/4" x 1" steel flat to form a cage around the action. Then I will weld half a 1/2" pipe coupling to the flat and screw in a 24" piece of pipe for a leverage arm. All because I'm too cheap to spend the $60 bucks Midway wants for the real thing. I'd go out to the barn and get it welded up but I caught a downright awful cold and don't feel like getting off the couch this evening.

I remember reading here some time ago - put the wrench on, cheater bar on the wrench, hang a bucket of sand on the cheater bar. Come back in the morning and the bucket of sand is on the floor and the barrel is loose.

[Goatwhiskers]

Use wet sand, works better. GW

[David2011]

John Taylor gave excellent advice. I've never gotten a Mauser action and barrel separated without a hefty impact on the action wrench. Soak in Kroil a day or more, clamp the barrel TIGHT, Take a good swing at the action wrench with a heavy hammer or bar of 2" steel.

David

[fguffey]

I have an action wrench? that does not have a handle. All four corners are flattened/upset. It was made of one solid piece of metal and does not split or separate.

F. Guffey

[MBTcustom]

Pardon me for coming in late, but why is everybody trying to adjust sights with an action wrench?!?!
The OP didn't say he had a headspace issue, he said he had an issue with his sights!
He said the extractor groove was correctly aligned in the barrel tenon, so why did everybody tell him to take off his barrel and set the shoulder back????
Seriously, you do realize that the sights on a Mauser rifle are soft soldered in place? You heat them just a little with a standard propane torch and you can put them anywhere you want them to be?
I just installed a new barrel on a Yugo last week and it didn't come with sights, so I took the ones off the original and transferred them to the new barrel, which took all of 20 minutes start to finish!
The sights should be set with levels on the underside of the action and the top side of the rear base and the front dovetail. Once you get them set, just heat them up until the solder beads show, and you're done.

[Deep Six]

Pardon me for coming in late, but why is everybody trying to adjust sights with an action wrench?!?!
The OP didn't say he had a headspace issue, he said he had an issue with his sights!
He said the extractor groove was correctly aligned in the barrel tenon, so why did everybody tell him to take off his barrel and set the shoulder back????
Seriously, you do realize that the sights on a Mauser rifle are soft soldered in place? You heat them just a little with a standard propane torch and you can put them anywhere you want them to be?
I just installed a new barrel on a Yugo last week and it didn't come with sights, so I took the ones off the original and transferred them to the new barrel, which took all of 20 minutes start to finish!
The sights should be set with levels on the underside of the action and the top side of the rear base and the front dovetail. Once you get them set, just heat them up until the solder beads show, and you're done.

So I just heat them up, rotate as necessary, and then let them cool? If it's really that easy I'll have to give it a try...

[MBTcustom]

Yes. That's what I'm saying.
It's not even silver solder usually. You can melt it with a propane torch.

[fguffey]

Due to my perfectionist tendencies with guns, I don't like option 1. Option 4 would be easy (I have the drilling jig) but I loose the historical value/feel of the rifle. Option 3 is a mess with all sorts of consequences. Option 2 would be relatively simple, but I've never done high-temp soldering before and don't really know where to begin with it

I would assume by now you are finished, but if you decide to heat and then roll the sights ask Goodsteel if there is anything he left out and or omitted. I have never seen a Mauser that did not have screws holding the sights in place, one in the front and one in the rear, both are hidden, so it would be a mistake to assume the sights can be heated and then indexed.

Alignment and lever, if a lay out table is used, square the bottom of the receiver then install the sights with a square.

F. Guffey

[MBTcustom]

I would assume by now you are finished, but if you decide to heat and then roll the sights ask Goodsteel if there is anything he left out and or omitted. I have never seen a Mauser that did not have screws holding the sights in place, one in the front and one in the rear, both are hidden, so it would be a mistake to assume the sights can be heated and then indexed.

Alignment and lever, if a lay out table is used, square the bottom of the receiver then install the sights with a square.

F. Guffey

Shoot, you're right.
While you're at it, remember to drift the cross pin out of the rear sight, Push down and back to remove it. Then, remove the sight spring by pulling forward on the tongue. Remove the elevator ramp by hinging it forward and up.
I'm having trouble remembering where this hidden screw is on the rear sight (must be different models than I'm experienced with) but the front screw is located under the front sight blade. If it's stuck, don't sweat it. If it's a problem, drill it out and go on ahead. The solder is plenty of holding power. Personally, I would leave the screw out.

[Deep Six]

Yeah I gave up on the action. I built a proper action wrench with a 2' handle. I was pretty much jumping up and down on the end of it but it wouldn't budge. I was at that point where any more trying and something was going to shatter and launch pieces of action across the room, so I quit.

I did find the screws on the sights so I think I will try rotating them. Just been too busy with springtime chores to mess with my rifled toys lately. The property, buildings, and internal combustion engines have been consuming all my free time. Maybe this weekend I'll get to it.

[fguffey]

Yeah I gave up on the action. I built a proper action wrench with a 2' handle. I was pretty much jumping up and down on the end of it but it wouldn't budge. I was at that point where any more trying and something was going to shatter and launch pieces of action across the room, so I quit.

I use a hydraulic press to hold the barrel, I have a 2' handle on the action wrench, I have a piece of 4' black pipe I use as an extension. I weight 300 pounds, 300 pounds X 4 feet is 1,200 foot pounds of torque. Point? Your sights did not align for the lack of trying. Friends attempted to remove a barrel from An M1917 Eddystone, there were only 3 of them trying, there would have been 4 of them but there just was not enough room for the fourth. It reminded me of the early days of tubeless tires.

F. Guffey

[nekshot]

Yes. That's what I'm saying.
It's not even silver solder usually. You can melt it with a propane torch.

I won't argue about what the solder is but I have changed alot of mauser barrels and if I could ever get my solder to hold like that stuff I would be a happy camper!

[MBTcustom]

I use a hydraulic press to hold the barrel, I have a 2' handle on the action wrench, I have a piece of 4' black pipe I use as an extension. I weight 300 pounds, 300 pounds X 4 feet is 1,200 foot pounds of torque. Point? Your sights did not align for the lack of trying. Friends attempted to remove a barrel from An M1917 Eddystone, there were only 3 of them trying, there would have been 4 of them but there just was not enough room for the fourth. It reminded me of the early days of tubeless tires.

F. Guffey

So why go through all that? Im still trying to understand why anybody would prefer that to gently melting the solder and indexing the sights?
What am I missing here?

[fguffey]

Yeah I gave up on the action. I built a proper action wrench with a 2' handle. I was pretty much jumping up and down on the end of it but it wouldn't budge. I was at that point where any more trying and something was going to shatter and launch pieces of action across the room, so I quit.

I did find the screws on the sights so I think I will try rotating them. Just been too busy with springtime chores to mess with my rifled toys lately. The property, buildings, and internal combustion engines have been consuming all my free time. Maybe this weekend I'll get to it.

He is doing what I would encourage him to do. He acquired a rifle that has sights that are not aligned, from the beginning he indicated he was not interested in melting the solder between the sights and the barrel, now he is aware the sights are not only soldered but are held in place with a small screw, as he said "I found the screws", he is acquiring knowledge and skill.

Now he is having trouble removing the barrel. I do not have trouble removing barrels, I set-up once. I do not progressively move up from easy to remove to the most difficult, I start my set up for the most difficult.

What are you missing? I am under no obligation to make any attempt to understand what the OP is asking, but I make every effort to try. His barrel was not indexed, his barrel was removed from another rifle and then installed on his receiver. I do not know how much effort was used to correctly index his barrel but do know the threads could be pulled and the mating surfaces could be galled and there is stress, so the effort to index his barrel failed. I know, there is only stress when the receiver is an M1917 Eddystone.

I have a knocker receiver wrench, all four corners are flattened, I also have 48" pipe wrenches that fit across the flats, use the pipe wrench, if the wrench fails I have big hammers for JIC, as in 'just in case'.
When someone is having trouble the worst advise that can be given is 'all you gotta do is etc.' there is nothing wrong with explaining why the problem seems so difficult.

F. Guffey

[David2011]

I got caught up in the questions of breaking the barrel out of the receiver. After Goodsteel's post, I have to agree that heating the sights to soften the solder is the way to go. It's VERY easy with just a propane torch. The OP says the extractor cut is indexed properly. I've removed many Mauser barrels and they were all soft soldered. The screw is redundant and may have just been used to position the front sight while it was soldered; I really don't know. The solder alone will hold the sight from now on.

David

[fguffey]

I got caught up in the questions of breaking the barrel out of the receiver. After Goodsteel's post, I have to agree..... The screw is redundant and may have just been used to position the front sight while it was soldered; The solder alone will hold the sight from now on.

David

David, the screws may be redundant but they are also hidden, something like a belt and suspenders or JIC as in just in case. A skilled smith installed the sights with the screw, someone down the line added heat. Who knows, it is possible the solder was never intended to hold the sight, it is possible the solder was used to fill the gap to prevent dirt, grit and grime from building up between the sight band and barrel.

F. Guffey

[David2011]

Yeah, since the designer left us long ago all we can do is guess at the intent. For sure belt and suspenders; the solder certainly kept corrosion from forming under the sights as well. It certainly made for a sturdy installation for combat use. I have removed a lot of Mauser factory sights when I was instructing gunsmithing classes where the thrust of the class was building a sporting rifle on a Mauser action. They were all well soldered with soft solder.

David

[Deep Six]

I realigned the sights last weekend. They broke loose with some heat from a propane torch just like everyone said. Now they're perfectly lined up at 12:00. I also finished bedding the action/barrel in the original stock. It's tight as a drum now. I hope to shoot it this week. I may have to swap in a timney out of one of my commercial 98s to do the accuracy tests. The trigger it currently has is a real piece of work - and that's coming from someone who isn't very sensitive to bad triggers.

Thanks for all the help and suggestions.