Planning out a 10.75X68 build

[Luederitz]

I could guarantee you 1 secured royal Bengal tiger .

Without his right arm he will not be able to shoot the tiger...

 

[HWL]

Without his right arm he will not be able to shoot the tiger...

You are right, should the tiger gets the arm.

But I think, Major Khan will give back my arm.

HWL

 

[Excessexpress]

the 10.75 x 68 got a bum rap in the beginning with bad bullets of improper weight, and properly loaded it duplicates the 450-400s with a 400 gr. bullet at 2150 FPS and that's certainly no wimp!! I built a couple of them, on 98 Mauser actions with drop box that held 5 down and one up, a definite plus when needed..I have a world of respect for that caliber used with handloads and Woodleigh 400 gr. bullets...I could never tell any difference in killing effect or reaction between it and my beloved 404 Mauser or 450-400 double rifles..

Its only downfall has been availability of brass..

And here we have it.

The projectile does the killing, the cartridge merely delivers it.

Could it take care of Dangerous Game ? With appropriate projectiles, yes. Would it be my first choice when deliberately choosing such game? No. I would choose something with more oomph.

I wouldn’t let it stop me building a rifle though, in fact I seriously considered it at one point, before deciding on a smaller cartridge for that action

 

[RayAtkinson]

Your sure getting a lot of opinnions from those who have never shot or seen a 10.75x68!!
I built one some years ago and another sometime later, took them to Africa and shot buffalo, Hippo and PG..Sometimes something different adds to the fun and that's what hunting is all about, and using an unknown adds to your knowledge of firearms, Ive triad to use every caliber imaginable in my lifetime of hunting, same with bullets, Im an old bullet digger and have shoe boxes of recovered bullets..

The 10.75 got a bad rap because of the 347 gr. bullet that was too soft. A bullet we don'thave to deal with today as you can use 350 gr., 400 gr. and even a 450 gr. Woodleigh. It shoots the 404 bullets and easy to come by..I shot the 400 gr. Woodleighs for the most part and at 2134 FPS, a duplicate of the 450-400 a very popular caliber back in the day and still is today..The 1075 x68 can be built into a very light rifle on any std. Mauser action, m-70 Win, Rem 700, FNs and it will take an extra round in the magazine..It is a very good killer of DG including elephant with solids..and some consider the extra round a plus, and Im sure it can't hurt a thing...and if you tire of it, or dislike it all you have to do is chamber it out to a 404 Jefferys..BTW recoil to me felt less than my 375 H&H and in a much lighter gun..

So whats so bad about that, build a 10.75x68, you will love it, its a fun gun...The only problem is that brass was hard to find and only Horneber made it back then and I got that from Old Western Scrounger and Huntingtons as I recall..

 

[bushy]

G'day One Day this is an incredibly informative post thanks for taking the time too write it, I don't suppose you would know the dimensions the feed rails should be for the 9.3x62 cartridge or 9.3x64 Bren or where such information may be found?

Cheers Bushy

Yes indeed.

Different lengths also mean different shoulders location and characteristics in bottleneck cartridge designs.

In this case:

• The 8x57 case head measures 11.95mm, therefore: 0.866 x 11.95 = 10.35 +11.95 = 22.3mm. Add 0.1 mm for tolerances in cartridge dimensions and field damage. The magazine box must be 22.4mm at the case head.
• The 8x57 case measures 10.95mm at the shoulder, therefore: 0.866 x 10.95 = 9.48 + 10.95 = 20.4mm. Add 0.1 mm for tolerances in cartridge dimensions and field damage. The magazine box must be 20.5mm at the shoulder.

• The 9.3x62 case head measures 12.1mm across the rim, therefore: 0.866 x 12.1 = 10.48 + 12.1 = 22.6mm. Add 0.1 mm for tolerances in cartridge dimensions and field damage. The magazine box must be 22.7mm at the case head.
  
• The 9.3x62 case measures 11.45mm at the shoulder, therefore: 0.866 x 11.45 = 9.92 + 11.45 = 21.4mm. Add 0.1 mm for tolerances in cartridge dimensions and field damage. The magazine box must be 21.5mm at the shoulder.

• The 10.75x68 case head measures 12.6mm across the rim, therefore: 0.866 x 12.6 = 10.9 + 12.6 = 23.5mm. Add 0.1 mm for tolerances in cartridge dimensions and field damage. The magazine box must be 23.6mm at the case head.
  
• The 10.75x68 case measures 12.2mm at the shoulder, therefore: 0.866 x 12.2 = 10.6 + 11.45 = 22.8mm. Add 0.1 mm for tolerances in cartridge dimensions and field damage. The magazine box must be 22.9mm at the shoulder.

In consequence:

• A magazine box for the 8x57 must taper from 22.4mm to 20.5mm, and the rail relief must be located at the proper location.
• A magazine box for the 9.3x62 must taper from 22.7mm to 21.5mm, and the rail relief must be located at the proper location.
• A magazine box for the 10.75x68 must taper from 23.6mm to 22.9mm, and the rail relief must be located at the proper location.

While I do not think that a difference between 8x57 and 9.3x62 of 0.3mm in magazine width at the head would make a huge difference (although it would have bothered Paul Mauser), a difference of 1mm in magazine width at the shoulder begins to be meaningful, and a difference of 5.6mm in the position of the shoulder (46.2mm from head for 8x57 and 51,8mm from head for 9.3x62) is meaningful for the cut of the relief in the rails.

So yes, the difference of 1.6mm in the two cartridges overall lengths is likely meaningless, and they fit in the same action length, but they ideally need two different magazines and rails geometry. Granted, the differences are small in this scenario, and the 9.3x62 will likely work in an untouched 8x57 action, but modifying the magazine and rails per the above calculations is what makes the difference between a rustic re-barrel job, and the refined conversion job that translates into 100% reliable and butter smooth feeding.

When it comes to moving from 8x57 to 10.75x68, the difference of 1.2mm in magazine width at the head and 2.4mm at the shoulder will make a significant difference and a difference of 7.2mm in the position of the shoulder (46.2mm from head for 8x57 and 53,4mm from head for 9.3x62) will be important for the cut of the relief in the rails.

This is why converting the standard M98 to .416 Rigby was such a delicate process, because in addition to having to cut 13mm (!?!?!) off the feeding ramp (and lower lug recoil shoulder), the magazine and rails had to be widened 5.5mm (!?!?!?), not to mention opening the bolt face to its almost full diameter...

 

[Hunter-Habib]

When I hunted in Kenya for my first African Safari in 1974 , I saw a couple of 10.75x68 mm Mauser Oberndorf rifles in the hands of a few native hunters . Old colonial era rifles . The natives had a dusting of different ammunition brands for them : old ICI Kynoch 347 Gr FMJ solids and split points , old DWM 347 Gr FMJ solids and soft points and old RWS 347 Gr FMJ solids .

Our white hunters really didn’t like this caliber for dangerous game , at all . Most were using .375 Holland & Holland Magnums or .458 Winchester Magnums ( which they didn’t like very much either , but used because it was the only big bore for which factory ammunition was being made in the 1970s ) , at the time . This caliber is very marginal for most dangerous game . And simply doesn’t make the cut for elephant . Regardless of how hot you load it , I don’t think that it has the necessary punch to get a bull elephant with a frontal brain shot . Case capacity and sectional density are just not good enough . In my opinion , the .404 Jeffery is a far superior choice among the .423 calibers .

Still , if you want to build one , it’s going to be relatively easy . Any standard length action will do . Like a Winchester M70 , BRNO ZKK600 , or military surplus Mauser 98 action . Douglas barrels or Safari Outdoor can build you a barrel for it .

I did see this caliber in use in Nepal , though . The hunter downed a couple of Tahr with it . Seemed to work on them well enough.

 

[John Telford]

As a collector of classic bolt action rifles from the “Golden Era” of Safari I really get a kick out of hunting with these rifles when time/ conditions permit. And so it was that I found myself with some spare time on a hunt having successfully guided my mate from Philly onto a fine Oryx with a few days to spare. I decided a while ago use my 10.75x68 on my “50th” Buffalo hunt - ( a gift from my wife for my 50th birthday) however the original Kynoch ammo was only giving me 1950 or so fps. I then decided to rather use one of my 404 Jeffries for this task and decided to try for a nice Eland bull instead with the x68.
Well after a fairly long day on the spoor I finally connected with a herd of Eland and drew a bead on a fine bull. Wow was I surprised by the outcome of this caliber! The original ammo wacked this bull good and proper going right through the animal at an oblique angle from the shoulder and out the opposite rib cage. I’m not even sure of the bullet weight which I think is 400gns? Distance was about 50 meters and the bullet went exactly to point of aim. Obviously this rifle was regulated for this ammo! The bull did manage to run about 40 or so meters before collapsing dead. It was really a fantastic hunt and what made it more memorable was that it was the tracker David's last hunt before retirement. He is 62 and was PHASA tracker of the year 2019 (age 60)! This old chap was born on this farm and hunted with some of the old timer Lion control hunters in the 1960’s. He told me many interesting tales about the old days when for example he was required to urinate on old man Steve Van der Walt to mask the white man scent before a Lion hunt. After my firsthand experience with this caliber I would not hesitate to use it on a Buffalo. Elephant would be a possibility but why take the chance? Yes Andrew Holmberg shot his biggest elephant with this caliber -156 pounds but that was in a different era.
So to anyone wanting to use this in Africa for large game up to buffalo i believe it would suffice. T&C’s apply much like those attached to the 458 win.
This Orbendorf Mauser rifle was made in 1924.

 

[John Telford]

Ammo used was Kynoch 347 gn solids.

 

[Wishfulthinker580]

Ammo used was Kynoch 347 gn solids.

Pics of your rifle?? I’m curious about the cartridge. 400 grain Woodleighs at around 2150 fps sounds like performance close to the 450-400 or the original loading for the 404 Jeff

 

[John Telford]

I wrapped the wood with camo tape to protect it a bit!

 

[sestoppelman]

With a case capacity nearly the same as the .375 H&H, using good bullets at anything over 2000 fps, it would be a pretty good round.
Much of its poor reputation stems from the poor bullets it used, both weight and construction.
If brass was available in any kind of quantity, I think it would be an interesting project and totally adequate for buffalo.

 

[Wishfulthinker580]

I wrapped the wood with camo tape to protect it a bit!

That’s a great rifle! I really like the style of those pre war commercial mausers

 

[Wishfulthinker580]

With a case capacity nearly the same as the .375 H&H, using good bullets at anything over 2000 fps, it would be a pretty good round.
Much of its poor reputation stems from the poor bullets it used, both weight and construction.
If brass was available in any kind of quantity, I think it would be an interesting project and totally adequate for buffalo.

That’s what I was thinking but you’re right. The brass is the problem unless you got lucky. Ken Owen has one for sale that got me to thinking about it

 

[HWL]

The brass is the problem unless you got lucky.

Brass is available from https://huelsenmanufaktur.de/de/produkte

HWL

 

[Foxi]

The caliber was popular in the French colonies between the world wars.
tn the effect on big game it surpasses the .375 by far.
Why not bring an old Mauser caliber back to life.
It's fun.

 

[Chris S]

Brass is available from Bertram brass in Australia. I have one put together on a zkk600 action that functions well so a long action Cz or Brno action is a good bet.

 

[Wishfulthinker580]

Brass is available from https://huelsenmanufaktur.de/de/produkte
View attachment 424764
HWL

Thank you sir! I’m still mulling things over but the x68 is on my radar. I will keep them in mind. I’m always intrigued by the rare and odd cartridges (as they are seen by the majority in the US).

 

[Wishfulthinker580]

The caliber was popular in the French colonies between the world wars.
tn the effect on big game it surpasses the .375 by far.
Why not bring an old Mauser caliber back to life.
It's fun.

Thank you! I’m definitely considering it. What manual is that data from? The Woodleigh manual shows their 400s running a little “hotter”.

 

[Wishfulthinker580]

Brass is available from Bertram brass in Australia. I have one put together on a zkk600 action that functions well so a long action Cz or Brno action is a good bet.View attachment 424749

The one that I’m considering is built on a mil surp BRNO action.

 

[Foxi]

Thank you! I’m definitely considering it. What manual is that data from? The Woodleigh manual shows their 400s running a little “hotter”.

Author is German reloader Norbert Klups.
"reloadung for hunter"
Dont belive its avaliable in English.