8,0 n

[blucher]

I have an old factory original mauser type B sporting rifle probably made in 1913. When I received it, the front sight was knocked off and I tinned then sweated it back on using 50/50 solder and rosin flux so as to avoid creeping rust over time. The caliber is 8,0 N. From my understanding this is 8mm J. Using Jon Speed and some various internet forums posts as sources, the 8,0 N that is prior to WW1 was for only 8mm J, however post WW1 the mauser factory reamed the neck of the chamber to allow the larger .323 S diameter round to be safely fired without the brass cartridge case failing.

Does anyone have any further information on the caliber 8,0 N?

Thanks,
Tristan

[blucher]

Additional markings: land dia, groove dia, rifling twist rate, bore gauge number, proof marks.

There's an S by the proof marks you can make out in the picture. While not in the same place, this reminds me of the S stamped on Gewehr 98 barrels to indicate it being used for the larger diameter 8mm S round bullets. However that does not make sense to signify that given the rifles year of manufacture. Does anyone know what this S stamp means?

[Axel E]

Your Mauser was originally meant ro use the 8x57 I, .318" load, that was the hunting rifle standard of the time. 8N(8 mm normal) means just so. But it may be used as well with the 8x57 IS, .323" loads, even the European CIP spec full power loads. Contrary to popular belief the barrel diameters, bore/land and groove, are not as important as the neck and throat dimensions of the chamber. The factory barrel dimensions, bore 7.85 mm = .309" and groove 8.15 mm = .321", are just midway between modern CIP 8x57I, 7.80 mm = .307 and 8.07 mm = .318, and 8x57 IS, 7.89 mm = .311" and 8.20mm = .3228" minimum specs.
As the 1934 and 1940 RWS handbooks put it:"There is rarely a problem in firing S bullet ammo in an I barrel bolt action rifle, but in break-open guns, combinations and drillings accidents may happen due to the much thinner barrels."
If you are over cautious, buy a box of the emasculated SAAMI specs "8 mm Mauser" loads by Remington or Winchester first. These are loaded with .321" (should fit your bore perfectly!) 170gr bullets to about 2400 fps, at a grossly reduced pressure to make them safe in any old military M88 Commission rifle, even with undersized chambers in the thin military barrels. After shooting a few of these in your rifle, try to slip an 8 mm S, .323" bullet into the unresized neck of the cases. If the .323" bullet slips in and out the case neck without much force applied, you may use CIP spec 8x57 IS loads too, typically .323" 196 gr at about 2460 fps.
156.14 is the old gauge number for a bore/land diameter from .310 to .320". I don't see an S in your photos, just the then usual Mauser crown/B and crown /U proofmarks.

[blucher]

Axel thanks for the information.

Attached is a better picture of the S on the underside of the barrel.
I've chambered both the .323 JS round (prvi partisan, since that's Serbian manufactured I'm guessing that is a true .323 bullet although I haven't pulled a round and measured it) and the .318 J round in the rifle. I can feel the JS round requires slightly more force in closing so I'm guessing I'll probably only fire the Remington and the J bore ammo out of this.

I was wondering if you could tell me what each of the individual proof marks mean on the receiver and barrel?

[Axel E]

was wondering if you could tell me what each of the individual proof marks mean on the receiver and barrel?

That S was a factory internal marking,meaning unknown. At that time the proofhouse at the mauser factory stamped the commercial sporters only with the crown/B = Beschuss = proofload fired and crown/U = Untersuchung = inspected/viewed for defects. Why mark the obvious? Until after WW1 commercial Oberndorf Mauser 98 guns were always rifles, so no need to mark then crown/G 0 Geschoss = solid bullet or crown/N = Nitro, as no 98 rifle then could use a black powder cartridge. Both latter marks came into use by the oberndorf proofhouse in the 1920s only, when Mauser rifles were converted to shotguns and the "Wehrmannsgewehr" target rifles were built for the originally blackpowder 8.15x46R.

[blucher]

Axel, thanks for the reply and insight. I appreciate it.

[Axel E]

PRVI Partizan lists different loads with identical .323" bullets and identical cases:
"8x57IS" loaded to CIP specs: 175 gr softpoint at 2540 fps mv, 196 gr sp at 2460 fps
"8 mm Mauser" loaded to SAAMI specs: 175 gr sp at 2330 fps, 196 gr sp at 2180 fps