Home
A commercial Oberndorf Mauser barreled action in original 10.7x68. Pix below. Contemplating converting to 404 Jeffery. Seeking detailed "how to" steps required for competent gunsmith to perform such conversion.
Found some four decades ago, at the 'high end' Beinfeld Antique Arms Show in Las Vegas.
Something of a 'time warp' commercial Oberndorf Mauser barreled action in 10.75x68 and looking just about brand new! 'IF' it is refinished, masterfully accomplished! The seller purporting it to be prepared for rechambering to 404 Jeffery. All original & matching but for the bottom metal assembly which is original Obie magnum mauser length. Such serialed to itself. He was selling it as "too many projects". Now, some four decades later & having done nothing with it, to do that conversion soon or sell under same excuse!
This post isn't about selling. I'm just looking to get a handle on exactly what would needed for a proper quality conversion. Detailed instructions concerning all steps necessary from original chambering indicated to the Jeffery. A central question also any action rail modifications typically necessary.

Thanks for guidance!
Happy Holidays & Be Safe!
John

Attached picture R9 Action R.jpg
Attached picture R9 Left Action.jpg
Attached picture R9 Action Top.jpg
Attached picture R9 Multi-Leaf Sight.jpg
Attached picture R9 Front Sight.jpg
The 10.75x68 mauser is my favorite. You are a lucky man! That barreled action is in great shape.
First off, IMHO, it would be a shame convert it to 404. I understand that ammo and brass hard to find, but it would be a shame to butcher such a nice piece. That is a Type A barreled action, and VERY rare. However, if you must convert it, I would recommend finding a Duane Wiebe, or James Wisnef 404 bottom metal. Both are now out of production, but if you placed an add in the 24hour and/or Accuratereloading.com classicifieds, one might turn up. The Wisner units have a larger guard bow more in the Oberndorf shape. The 404 Jeff is a 3.5”+ length cartridge and fatter than the typical magnum cartridge belt. There is nothing “magnum” about the 10.75x68, that Mauser receiver or bottom metal of yours. Your mag box would need to be extended in the front, as it currently about 3.3” inside length, or maybe a little less. The feed ramp will have to a lot of metal removed and made to match the new dimention of the extended new or modified bottom metal mag box. The feed rails will need to be opened up quite a bit. All of this neither for an amateur or the faint of heart. I know Steve Bertram in Colorado. He has done at least a couple of these conversions, and he make up a stock, as well. He is a member of the American Custom Gunmakers Guild. Duane Wiebe or James Wisner are other guys worth contacting, as well. I wouldn’t try doing the work yourself. It would be a shame to ruin that action.

You said your not interested in selling. However, if you change your mind, I’m very interested! I have several boxes of RWS 10.75x68 factory ammo, a pattern Type A stock that I had made from a an Oberndorf Type A in 9.3x62, a lovely California English walnut blank from Steve Heilman. I would make that barreled action sing again!
I'm right there with yah Matt. If a guy is patient, he can have a friend send a pile of 10.75x68 RWS brass international mail from Germany. Maybe Huntington (rws dealer) could special order it. Plenty of American soldiers over there in Germany that could help. Just an email away.

The standard action 416 ruger has saved me from the desire to pursue an original 10.75x68 oberndorf sporter.

But gawd dmn is that an original to be proud of!

Theres something about the ORIGINAL Oberndorf bolt actions. They make everything else feel like an arrogant rip off.
You said it all perfectly, indeed! 10.75x68 brass is currently only made by Huelsen Horneber and only sold through Reimer Johannsen. It’s not cheap! However, it can be made from 458 Lott, 416 Rem Mag, or 375 H&H brass. Buffalo arms makes and sells it this way. Turning the belts off is the only hard part. There is a custom brass outfit in Texas that makes custom lathe turned brass. They told me they can make it for something like $5.00 a piece with a minimum of 40, if I recall correctly.
https://www.grafs.com/retail/catalog/category/categoryId/863
[qu


That brass hasn’t been imported for a couple years. I have 60 pieces, or so. The dimensions are all over the place, with rim diameters varying something like .008”. While I haven’t fired any, reports indicate it is very week brass. ote=elkhunternm]https://www.grafs.com/retail/catalog/category/categoryId/863[/quote]
Dennis Olson Plains MT is your man.
Your rifle, so do as you please, but I'd love to see that restocked in its current configuration. It would be the gem of any Mauser collection.

A 404J is cool, but it isn't THAT!
Thanks much for all the kind & very good advice in several dimensions/directions. With the additional info re possible ammo and no sign of elephants in our SoCal backyard... I do think I'll pause and further consider leaving the chambering as-is in x68. Ammo 'availability though even not Walmart,,. a new dimension! I do now have several interested buyers despite even 'not for sale'.
No plans to do anything more with it until this Covid mess at least under control! To you who did experss interest, I have your names!

Again, thanks for the "thoughput!" smile
Best & Happy New Year!
John
Yes sir I would be interested in that if you decide against your project
3,900 ft-lb’s
© 24hourcampfire