Mauser K98K Headspace Problem
I recently purchased a German Mauser K98K from Mitchell's Mausers. (Please - no comments about the issues/problems with Mitchell's. I'm well aware of them. Additionally, I purchased the gun to be a "shooter" and not a "collector.")I asked if the headspace was checked. The sales agent informed me that all of the parts are gone over and safety is checked - including the headspace.
The times that I have fired it I had evidence of burnt powder residue that ran the length of the brass, to the bottom of the shell and on the bolt face. There also was some evidence of powder residue in the gas ports on the bolt. I checked the headspace myself myself with a 8mm Mauser "field" gage made by Forester that I purcahsed a few weeks ago. I took the extractor and extractor ring "ring" off as the instructions state. The bolt closed with no problems. So, I'm guessing that the headspace was not checked.
I realize that I will need to take it to a gunsmith. My questions are: 1.) Is this a common problem with Mauser K98K's? 2.) Can it be corrected? 3.) If so what are the options to correct it? and 4.) Will it cost me a small fortune to have it corrected?
The times that I have fired it I had evidence of burnt powder residue that ran the length of the brass, to the bottom of the shell and on the bolt face. There also was some evidence of powder residue in the gas ports on the bolt. I checked the headspace myself myself with a 8mm Mauser "field" gage made by Forester that I purcahsed a few weeks ago. I took the extractor and extractor ring "ring" off as the instructions state. The bolt closed with no problems. So, I'm guessing that the headspace was not checked.
I realize that I will need to take it to a gunsmith. My questions are: 1.) Is this a common problem with Mauser K98K's? 2.) Can it be corrected? 3.) If so what are the options to correct it? and 4.) Will it cost me a small fortune to have it corrected?
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IMHO Mitchell Mausers aren't worth screwing with. Military firearms made during wartime aren't made with the tightest tolerances. For a competent gunsmith to correct the headspacing to "YOUR" standards would entail removing the barrel, facing it off in a lathe one turn=360 degrees, and then rechambering it. His hourly rate will kill you, money wise. It just isn't worth it. Also shortening the barrel might mean that the upper handguard has to be altered=more money to the gunsmith. 0 -
What ammo were you shooting? Much US made 8mm ammo is very mild (too mild) and the case doesn't seal to the chamber properly, resulting in scorched brass like you describe.
Examine your fired case next to an unfired one. Has the shoulder moved foward? Is there a shiny ring or imminent crack near the base of the case?
If not, the headspace, while maybe not in tight spec, isn't causing any undue issues.
My approach would be this- have your gunsmith look for lug set back. If that isn't present and any headspace problems are just due to a deeply cut chamber, as long as you aren't seeing problems with brass stretch just shoot it. If however there IS lug set back, I'd call mitchells and tell them this and demand an exchange. They said they examined them all after all.
If you handload, you can correct the headspace by using fireformed brass and neck sizing only.
German chambers are usually pretty good compared to say British or Russian ones, but it was wartime and something that was just a little out of spec might get passed through.0 -
MM force-matches their bolts, so if it swallows the field gage, shelve it. Yer done.
Per great above advice, ignore all other symptoms ('cuz at this point, it's a cash pit).0 -
Call Mitchel Mausers and tell them headspace is out of spec and you want an RMA to return it for a properly headspaced rifle.
Military rifles have been tested to function outside the limits of no-go gages but as far as Ordnance practice goes they are unserviceable.
You should be governed by that standard and return the rifle.0 -
If you have soot or powder residue on the outside of the fired shells, you are under-loading them and not chamfering the inside of the case necks. Load to factory specs and properly chamfer the inside of the neck and you will eliminate the problem. 0 -
quote:Originally posted by cbyerly
If you have soot or powder residue on the outside of the fired shells, you are under-loading them and not chamfering the inside of the case necks. Load to factory specs and properly chamfer the inside of the neck and you will eliminate the problem.
It swallowed a field gauge, man!!
(Best to contact MM, and inform them of the hard evidence that you have of unserviceability)
Best, Joe0 -
Put two small discs of masking tape on top of each other on the bottom of your field gage and try again. Foster field gages are just under the max size for head space.
Remember you are talking about an old war horse of a gun, not a tight chambered bench rest barrel.
If the gage chambers with no resistance felt, it is too big. Bob0 -
hermiem,
First and foremost, one or two pieces of tape placed on a field gauge is not going to provide positive assurance of proper headspace.
Second, here is a little information for you to read, absorb and apply to your circumstances:
8X57 Mauser (8mm Mauser)
Chamber Headspace Variation and Measurement
Background
SAAMI's current Chamber and Cartridge drawing (ANSI standard) shows a 19? shoulder angle in the chamber. The earliest revision of this print showing 19? is dated April 21, 1980.
The shoulder angle in the 8 x 57 Mauser, however, hasn't always been 19?.
A SAAMI/Winchester Repeating Arms print, New Haven, CT, dated November 12, 1938, shows a 20? 48' shoulder angle. The last revision made on this 20? 48' angle print is dated July 9, 1947.
It appears that the transition from the older 20? 48' shoulder angle to the current 19? shoulder angle did not happen suddenly. Discussions with gunsmiths and collectors indicate that there may have been a 15 to 30 year period during which firearm chambers were manufactured to both shoulder angles.
Measurement and Gaging Implications
Headspace gages that are made to the current 19? shoulder angle will not properly check older 20? 48' shoulder angle firearms. Because of the shoulder angle difference, a 19? gage does not match to the datum measurement point of firearms that are chambered to 20? 48'. A 19? headspace gage will appear as if it were longer because the 19? shoulder angle will contact the bore of the chamber before it contacts the chamber's datum point.
Recommendation
Determine whether the chamber of a particular firearm is made to the current 19? shoulder angle or to the older 20? 48' shoulder angle. This may be done by making a chamber casting using CERROSAFEr or a similar material.
Once the shoulder angle is confirmed, then obtain the correct headspace gages. Forster manufactures distinct gages for both the current standard 19? shoulder angle and for the older 20? 48' shoulder angle chambers. Order numbers for the older 20? 48' gages are:
* GO Gage: HG8mmoldG
* NO-GO: HG8mmoldN
* FIELD: HG8mmoldF
Personally, I suggest getting a Return Authorization and shipping labels from Mitchell Mausers. Send the rifle back and either get a properly safety checked rifle or refund your money completely.
Best.0
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