doublegunshop.com - home Forums General Discussion German & Austrian Sporting Guns @ doublegunshop.com another Oberndorf sporter

picked up another this one has a plug gauge number of "156,14", not on my list. any ideas aboout the caliber?? Serial number is 110376. Mauser banner on receiver ring, militery style stepped barrel. thanks, Larry photos to follow..

156.14 = 7.87 mm = .310", so my guess is 8mm Mauser or 8x57 I (.318").

With kind regards,
Jani

Thanks, That seems to be right in line with the time frame this would have been put together. Does any one still make .318 ammo, or is this now a re-barrell project?

As I understand it, after a certain date Oberndorf Mauser sporters were all chambered to the same dimensions, irrespective of the barrel bore and groove diameter, which made them safe to shoot with either size bullet. If an 8X57IS round with the .323" bullet will chamber in your rifle and the bolt will close easily, it should be safe to shoot.

The easiest way to confirm this would be to fire an 8X57I (.318" bullet) through the bore and then check to see if a .323" bullet will easily pass into the mouth of the fired case. If it will, you have sufficient neck clearance and can use either bullet.

According to a published chart this rifle was made in 1931. Being a desirable original, re-barreling in not advised. If the bore happens to be in bad condition (worned out), I would consider re-rifling, such as from .318 to .323.

With kind regards,
Jani

Thanks guys, I will check it out.

Well, both a Norma 8x57 JS and a fairly current production Winchester 8mm Mauser chamber with no problem. Bore is near mint with some pretty deep grooves so the next thing to do is shoot it; then the hunt for a scope to fit the claw mounts.

Larry,
American made 8mm Mauser ammo is loaded to lower pressure and some with smaller dia.bullets(some Rem, at least,had .3215" bullet)in recognition of the possibility of being fired in"J" barrels(which were often over .318" any way).The thing to do would be fire one of the Win.rounds you have and see if a .323" will easily enter the neck, as mentioned above.If it will not, try a 32 Win. Spec.bullet(.321").If neither of these will enter(unlikely),then either dia can easily be sized to .318" and loaded with normal 8mm Mauser dies by changing or removing the expander button.
Mike

Good advice. I wonder if I can get a spitzer type bullet in .32 Win special. I am off to Germany for a couple of weeks and will shoot it when I get back. Thanks, Larry

Old Western Scrounger has 8x57j loaded but its 250gr lead gas check. I haven't tried these but other long heavy bullets I've tried wouldn't cycle through my j Mauser.