correcting mauser head space

[Nora]

Given a Mauser 98k with to much head space and a lathe, am I correct in thinking that in a nut shell.... It can be corrected by removing the barrel, trimming the shoulder and face back equal amounts, reinstalling the barrel and re cutting the chamber to proper spec?

Thanks in advance

Nora

Also the sights will be removed and will not matter.

[S.R.Custom]

The equal part is critical. (This assumes the Mauser barrel in question is currently seated correctly; Mausers don't seat on the outside shoulder.) The inner shoulder --or face as you call it-- is turned such that it's .0015" 'longer' than the outer shoulder. That relationship must be preserved.

[waksupi]

As long as you use the same cases in the rifle, you can fire form them out by loading light, and having good contact with the rifling. This will blow the cases out, and will work in that rifle, as long as you stick to neck sizing only.

[missionary5155]

Good morning
+1 on what Waksupi stated. Unless you just want to try your hand at the job. I would shoot it as is segratating brass to that rifle.
I do this with all my firearms... except for ammo intended to be expendible. All my bolt, single shot rifles are still using brass that has been loaded many times. Neck sized only ever since I read in my old Speer manual #10 that it would extend brass life...

[akajun]

Hold up there fella, you might not have a problem.

Do you see signs of excess headspace in firing the rifle? Do the numbers on the bolt match the gun? Is this a "russian capture"? It may still be ok.

I take it this gun is still in 8mm. What country is it? THe problem with american headspace guages is that they dont reference the same point as the German, and other countries, chamber reamers. Same reason that you should use the same manufacturers guages with the reamer you use to cut the chamber. If anything, I would check it with a Field guage. If it does'nt close with a field gauge, or even if it does, but just barely or with force, Id shoot it and see what happens.

THen if I have a problem, before I turn the shoulder back and re cut the chamber, I would buy a couple of replacement bolts and try them and see if that corrects the problem. If you cut the shoulder back, you will have to re fit everything in relation to the wood " reat sight base, handguard, barrel bands, etc. Bolt bodies are only $25 each or so and you can turn around and sell what doesnt fix your problem.

[Tazman1602]

Define "too much headspace"?

If the bolt closes on a no-go gauge, but does_not close on a field gage, you can still shoot it. If it closes on a field gauge it either needs rebarreled or set back as you outlined.

As Waksupi said, just fire form your brass and then neck size only for that gun alone. Works just fine as long as the throat isn't totally shot out.

What you are talking about is "setting the barrel back one turn", a common practice last century with these rifles.

And S.R. is correct when he says the "equal" part is critical. You are supposed to have a "crush fit" of .0015 on the barrel as he says. Sounds easy, it is not unless you have a really nice lathe.

Let us know what you do and how you make out with it man!

Art

[John Taylor]

A little trick I learned from an old gunsmith a long time ago. Have the bolt lugs hard chromed on the rear. He would have more added than needed and grind it back with a tool post grinder in the lathe. May not be worth the trouble on an old Mauser but on some rifles it is more trouble to refit the barrel.

[Nora]

The rifle in question is a winter project that I picked up a last month. I'm calling it "Project Bubba". This rifle has been badly butchered 50 some years ago and has sat in a closet ever sense. I got this from my Pa-In-Law and am planning on reworking it to a respectable looking brush gun for deer.
It needs some major bolt work now and is currently close to being out of room for head space. (NG + .002 shim stock - .002 away from a field gauge) After reworking the bolt the head space will be completely shot.
I've never bothered to repair an old barrel before and have opted to just buy and install a new one from Brownell's. But with this being a winter project I'd like to try something new.
I have recently been given full access to a top notch machine shop so a quality mill and lathe is not going to be a problem.

Nora

[Tazman1602]

Hmmmmm. The bolt handle on that is very unique. Is that Braze I see?????

Art

[bohica2xo]

Just re-chamber it to 8mm-06.

Have done this more than once, and the cartridge is a nice improvement.

Hope you have the right tools if you plan to remove that barrel, they don't exactly spin out of there after 70 years.

B.

[scrapcan]

I like Bohica2xo thoughts on the project. If you are worried about dies look at using Hornady new dimension dies or lee dies.

[Moonie]

I have an old 98 that I got from the wife for Christmas with this exact problem, my plan first is to fire form brass in the rifle. If the rifle shoots acceptably I will probably rechamber to 8mm/06, if not I will rebarrel to 35 Whelen.

Then again I may just leave it alone, decisions decisions ;)

[kywoodwrkr]

With all that brazing on the bolt, if heat sink was not used, or not used properly, you may run the risk of softened lugs.
In other words, even after setting the barrel back you could have a time bomb.
Either try another bolt or at least have the current one hardness tested.
YMMV

[Nora]

Guess the bolt body swap is going to win out. I pulled the bolt out of one of my Russian front Mauser that swallows a field gage and tried it just for fun. Bubba's got a new bolt body it likes and will only close half way on a go gauge. A trip to the range will tell if this barrel is best left alone. (if it doesn't like to find the target it's going to get a 257 Roberts barrel) It slugs nice at .311/.322. It's slightly pitted and a little dark but I've had good luck with a lot worse.

[nanuk]

if it won't close on the "Go" but will chamber a factory round, it should work?

now, the issue would be, will you have problems resizing?

Could you lap the lugs to close on the "Go"?

[Nora]

Oops I said that wrong, it will only close half way on a NG gauge. That is just right in my book. Sorry for the misinformation.
I did take it out this after noon to see just what it would do. Shot 6 rounds at the 25 yard burm standing unsupported. The rounds I fired were sized for a different Mauser that I have and were bigger than optimal but with a 2 3/4" spread I think it is showing promise. The barrel will stay unchanged for the foreseeable future.

[John Taylor]

With all that brazing on the bolt, if heat sink was not used, or not used properly, you may run the risk of softened lugs.
In other words, even after setting the barrel back you could have a time bomb.
Either try another bolt or at least have the current one hardness tested.
YMMV

You would need to hold the heat at the rear of the bolt very high to effect the locking lugs. The lugs would need to go blue before the hardness would be change in the least. If there is a cock on open cam on the rear of the bolt body like most later rifles then the heat may be a problem in that area. I do a lot of bolt handle repair on Winchester model 70s, never seen enough heat transfer to the locking lugs to have a problem. I use a TIG torch for welding on bolt handles, plenty of heat.

[Tazman1602]

+1

I was just going there John. Even with an oxy/acty torch you have to use a LOT of heat to make that mistake.

.......then what usually happens is the heat sink breaks of inside the bolt................................don't ask me how I know that one.......<grin>

Art


You would need to hold the heat at the rear of the bolt very high to effect the locking lugs. The lugs would need to go blue before the hardness would be change in the least. If there is a cock on open cam on the rear of the bolt body like most later rifles then the heat may be a problem in that area. I do a lot of bolt handle repair on Winchester model 70s, never seen enough heat transfer to the locking lugs to have a problem. I use a TIG torch for welding on bolt handles, plenty of heat.

[leftiye]

Wrap the front part of the bolt in a wet cloth, use heat control paste, and an internal heat sink, MIG the weld?