Sporterized Mauser barrel question

**Rural Ruger** · September 27th, 2022, 10:37 PM

I acquired a sporterized (Gew 98) Mauser sight unseen from a local-but-online auction. Looked clean in the pics, likely 1960s or earlier modifications, high polish blue, nicely done stock, etc. Unfortunately, the reality is a little different once i got it in hand (recoil pad is toast, clearly been sitting for a long time, surface rust in the parts below the wood line, lower part of receiver and barrel spent time in a vice or pipe wrench). So all that has me questioning a few things. It was sold as an 8mm, but isn't marked anywhere for any caliber (polished away?).

On the underside of the barrel near the receiver (directly under the rear sight, but on the bottom of the barrel), there is a "section which is missing". It appears to be something in the way of a shroud, as there is still what appears to be a completely normal, undamaged barrel right underneath it. Other than the 'shroud' portion not being present, it doesn't appear to be abnormal...not like bubba just took an angle grinder or anything like that. And again, the 'internal barrel' part doesn't seem to be damaged in any way. Is this normal for a Gewehr 98? Did someone rotate the barrel and install the aftermarket sights on what used to be the bottom, leaving the former location of the rear site as this gap? Likelihood that the barrel is truly 8mm, or do i need to act as though it was swapped to xx caliber?

It wasn't terribly expensive and there is some potential there, but I'm not sure at what cost/not one i want to sink a ton of cash into. Was planning to grab a box of ammo and see if 8mm fits correctly in the muzzle and chamber as a starting point (figuring likely re-chamberings would probably be 30 cal), and if that seemed right, possibly do a test fire from a distance/via string to trigger. Or should i just be planning to have the chamber casted?

Thanks in advance...been a long time since I had a Mauser, and last one was not sporterized.

**Ecclectic Collector** · September 28th, 2022, 06:35 AM

On military mausers there is a shroud/sleeve that mounts the rear sight. I can see from the images it is missing and a dovetailed sporting type rear sight added. This base was soldered on, so it would likely leave traces if removed. (possibly forcefully explaining vise marks on action?) The real worry would be if the wrenching was done with enough force to warp the receiver. Unlikely but possible.

As for caliber: If you're certain the gun is a WW 1 era G98 then indeed the stepped barrel indicates it is still wearing a military barrel. A chamber casting would determine if it is still in the original 8mm Mauser chambering. However are you sure this is a German military issue gun? The G98 were made for a number of other countries in calibers like 7.65 and 7mm. Easy enought to check however.

Post WW2 sometimes saw conversion to a wildcat 8mm-06 wildcat round using 30-06 brass necked up to use 8mm bullets.

**Rural Ruger** · September 28th, 2022, 07:38 AM

Thank you, thank you! That is extremely helpful!

That shroud/sleeve would make a lot of sense with what I'm seeing, especially with your comments about solder...I was seeing traces of 'something' that I figured was either solder or epoxy (though I suspected the latter is less likely based on presumed age of modications).

Reciever is marked "1917, Amberg" so its definitely WW1 vintage. Age of modifications is old, I just dont know how old. 1950s maybe? I would think the Amberg means German issue, but correct me if I'm wrong please. Has a stepped barrel, as you said. Bore is surprisingly good too.

Wondering if headspace would be a concern?

Guessing the only way to tell if it was rechambered to 8mm-06 is via casting? Or I can try to chamber a 30-06 round too, if that's a viable option.

**Rural Ruger** · September 28th, 2022, 08:48 AM

30-06 goes all the way in to the case at the muzzle, also does not chamber. So maybe I am safe on the 8mm theory?

**Ecclectic Collector** · September 29th, 2022, 07:32 PM

The only way to know caliber for certain is to do that chamber casting. That said, it is most likely still in the original 8mm Mauser cartridge. It is your rifle and your personal risk. Do what you think most prudent to verify. A test firing secured in a bench and fired remotely with a string is a crude but simple way to check as well.

BTW: Amberg was one of the WW 1 German army makers for military Mausers, so almost certainly converted from an issue Gew 98 action. The original caliber designation would have been stamped on the barrel and would have been something like "7.92" as the German designation for the caliber was 7.92JS (J designating Infantry and S meaning designed for the .323 diameter spitzer bullet)

As for headspace: I bought a set of headspace gauges years ago. Used them to check all my rifles. Never found one that was in unsafe headspace. There are two gauges, Field and No Go. As long as your bolt won't close on the Field Gauge you are safe. A No Go simply verifies it is in spec. If the bolt closes on it, it is still safe, but on the loose side of things. I never had a German built gun test unsafe even with a mismatched bolt.

**Rural Ruger** · September 30th, 2022, 08:13 AM

Thanks again. Have a couple boxes of ammo and a new recoil pad coming next week, so will likely do a secured test fire once I get the pad ground to size.

Any signs of caliber must've been polished away long ago. Will eyeball it again once the ammo gets here to make sure it looks right though.

My best guess from all I've seen and what you've shared is that whoever sporterized it put all their effort into making the visible parts pretty (stock, polished barrel) and more or less ignored the rest.

**USMC3531** · September 30th, 2022, 10:07 AM

If nothing else use the scotch tape trick to get an idea if headspace is close before shooting.

**Ecclectic Collector** · October 1st, 2022, 09:53 AM

Check out YouTube for how to videos on cleaning rust on the underside of your action. Looks like you got a nice rifle once you can get things squared away.

Headspace gauges: Try this https://www.amazon.com/Z-P-V-Proizvo...-1-spons&psc=1

Or these: https://pacifictoolandgauge.com/saam...ce-gauges.html

**Rural Ruger** · October 3rd, 2022, 12:44 PM

Got it all pieced together and a new pad on, checked 8mm in muzzle and chamber, and did do tape test (thanks for the idea USMC)...all passable, so decided to test fire.

Put 2 rounds through it just for function over lunch, and both I and the gun are still in one piece. Brass looked ok, so gonna say I'm in the clear! Have some mild cleanup to do on the pad shape and fitment yet, but its close/workable now.

Thanks again both of you!