So, acquired a gorgeous large banner Mauser Type A, with a twist it seems. Advertised as a .30-06, I went to chamber a round today, and the bolt stopped significantly short of going into battery, like an 1/8” it seemed. I pulled the barreled action from the stock, and confirmed it’s marked .30-06 under the barrel... which it is, in a different font, right after some original markings that include “7,6, 7,85”... Took a .30-06 round and stood the bullet in the muzzle... it dropped snuggly into the lands / bore. Seems a lot like it’s an 8mm, maybe a .318” groove 8mm...

Now, not sure if it was just never rechambered, or if it was and is a short chamber 8mm-06 now, or something else. I’ll fire form a case without a bullet and see what I get.

In the meantime, what can the knowledgeable folks here tell me of the markings,

Angus

Thats Oberndorf marking under 30-06 barell. Slightly difference in twist rate compared to your specimen.
The rear sight on your "Type A" is not correct(only 3 folding blades )and a later ad.
Chamber cast may help to identify the chambering problem.

quote:

Chamber cast may help to identify the chambering problem.

I would do a chamber cast and slug the barrel before.

I would fire one round in it.

Have in mind that you can only chamber an unaltered Mauser out of the magazine box !

That's not a Type A to start with! Never seen one with an Octagan barrel. The sights are also not that of a Type A.

What you have not seen is not necessary what doesn´t exist.
Correct Type A octogon barell with the correct backsight.

Appreciate all input, I have held another half octagon Type A, as well with Express sights. Doesn’t mean it was original but suspect it was. There were few rules with Mauser on the Oberndorf Sporters all sorts of combinations were made, the barrel is properly marked on this one, and whatever she is original barrel or not, she’s pretty and was priced fairly. But she’s confounding as well.

Anyone able to help discern the 7,6 7,85.240 markings, and the 172,28? Also, anyone know of a barrel maker who could rebore to .330” (.318 WR)? I’d buy the new tooling.

The numbers 7.6, 7.85, and 240 are the bore, groove, and twist dimensions in millimeters. Converted to inches they are .299, .309, 9.5", respectively.

Many thanks, hugely helpful. Sounds like .30-06 afterall will chamber cast, slug it, and see what’s what.

quote:

Originally posted by Angus Morrison:
Many thanks, hugely helpful. Sounds like .30-06 afterall will chamber cast, slug it, and see what’s what.

Could it possibly have a very short throat and the bullet contacted the lands before the bolt would close? Just a thought.

Unfortunately there’s a bright ring around the shoulder of the brand new Federal cartridge I’ve tried to chamber in it, and no land marks.

quote:

Originally posted by heavenknows:


Thats Oberndorf marking under 30-06 barell. Slightly difference in twist rate compared to your specimen.
The rear sight on your "Type A" is not correct(only 3 folding blades )and a later ad.
Chamber cast may help to identify the chambering problem.

Good post and thank you, good info. Should this prove to be tinkered with imagine I’ll seek a rebore / rechamber to .318 WR.

An interesting combination of markings. The 7,6.7,85.240 mark has been explained above and it's certainly consistent with a .30-'06.

The 172,28 mark is the 'gauge' of the barrel (as in 12 gauge, 20 gauge, etc) before it was finish rifled. This was an earlier style mark and obviously not very descriptive. 172,28 gauge is equivalent to .300" and is typically seen on the various 8mm rounds, either .318 or .323 diameter. See http://germanguns.com/tech-corner.html

I'd definitely suggest a chamber cast and slugging the bore, even if it is also marked "30-06"

Does the serial number of the bolt match the action/barrel? It's hard to tell from the photos, but a mismatch there could also explain hard chambering.

The gauge number is correct for .300 .
Whatever happened to that barell/chamber.
It started its life as a genuine Oberndorf .30 US 1906.

Serials don’t match on barrel / action, and good stuff appreciate the info heavenknows and bpsteve. I over estimated the amount short of going into battery, dropped a .30-06 in the chamber with the bolt back and it is damn near there, like .050” short on headspace or something. Likely had this barrel fit at some point and whoever did messed up the headspace. Found a rebore if I have the stones to go through with it... could be neat to rebirth the .318 WR in a classic package.

Did you try shoving a round down into the magazine and then closing the bolt. Most mausers will not chamber if you drop a round into the chamber and then try closing the bolt. The extractor will not jump over the cartridge rim.

No such thing as a stupid question but unfortunately no, I’m an old hand with CRF, never chamber load them.

Ok just wanted to make sure. Really nice looking rifle. goood luck with it.

You will have to set the barrel back on the rechamber.

this is just a gut feeling but you might have a 30 X 57 there.
you can cut off an 0-6 barrel and clean it up with an X57 reamer easy enough.

I picked up an Arisaka that looked for all the world to be original and a 7.7 X 58.
it had been chopped @ 1/2" and then cleaned up to a 300 Savage.
pretty confusing to say the least for about a day.

Have you tried chambering a virgin unloaded 30-06
case with the extractor and extractor collar removed?