I found this very interesting cartridge in the Berlin-Karlsruher Industrie-Werke A.G. -früher Deutsche Waffen- und Munitionsfabriken KARLSRUHE i.B catalouge from 1926;



Would it be something for cewe when he has discovered that 8x68S wasn't enough for him (or the Baboons )

Does anybody here at AR have any information about the 8x75?

ALF where are you?

Blaser manufactures the K95 single shot in this caliber. The performance is between the 8x75 IRS and the 8x68 S, both also available for the K95.

There were, as indicated in the catalog, both the rimless as well as the rimmed version, both for the .318 and the .323 S bullets.

The 8x75 RS is the only one that survived and is still available today. Dies and cases are however expensive.

I have an exchange barrel for the K95 and use it with 180 grain Nosler BT, not at full power, though.

Husky:

The 8x75 and 8x75S and their rimmed brothers are based on the same case as the 9.3x74R (i.e., the same head dimensions as the 8x57). It was obviously designed for use in the magnum Mauser action, as the DWM 8x75 factory load that I have in my collection is loaded to an o.a.l. of 3.86" (with a long RNSP - I'm guessing probably a 227 gr.).

The 1932 Stoeger catalogue lists ballistics for the 8x75 and the 8x75R. It doesn't indicate which load is which, but presumably the slower one is for the rimmed round. The velocities listed below are those reported for 25m from a 72 cm (28.35") barrel:

bullet no. 354B, 10 g (154 gr) PSP, 790 m/s (2592 fps) and 890 m/s (2920 fps);

bullet no. 299A, 12.7 g (196 gr) RNSP, 715 m/s (2346 fps) and 800 m/s (2625 fps).

The circa 1938 RWS catalogue only lists the 8x75RS. They show it available with 12.1 g (187 gr) copper point, lead point or hollow point bullets at a 25 m velocity of 835 m/s (2740 fps) from a 65 cm (25.6") barrel. They also list 5 different 14.7 g (227 gr) bullets with no ballistics, as "Shortly to appear".

Hope this helps.

Cheers, Al

I think Chapuis offers its double rifle in 8x75R.

I use the 8x75RS in a Blaser K77, the forrunner of the K95. In this lite rifle, it is a hard kicker, but a powerfull cartridge. With 180grs NoslerBT i get 2900fps, but it is a quite soft bullet. Better are the 196grs like Norma Oryx, Woodleigh Weldcore and Blaser CDP. All these are able to get 2800fps with absolutly safe handloads using +-70grs R22, R905,N560 or Norma MRP.Or perhaps with a good 220grs like the long Woodleigh you can reach 2600fps!

The 8x75 is a fine cartridge either in rimmed or rimless!.
Would love to have a doublerifle in that caliber!


http://www.jww.de/r30/vc_content/bilder/firma445/Archiv...aden_jww_02_0205.pdf

It was my inspiration for my .300FGC. With same diameter as the 8x57, just 18mm longer. Cases can be made from 9,3x74R, like I do with my .300 FGC.

Sounds like it´s no match for the 8x68S but maybe pressures are lower?

quote:

Originally posted by cewe:
Sounds like it´s no match for the 8x68S but maybe pressures are lower?

Indeed. The 8x75 RS's max. pressure is 3.800 bar vs. 4.400 bar for the 8x68 S.

quote:

Originally posted by DUK:

quote:

Originally posted by cewe:
Sounds like it´s no match for the 8x68S but maybe pressures are lower?

Indeed. The 8x75 RS's max. pressure is 3.800 bar vs. 4.400 bar for the 8x68 S.

Originally posted by brayhaven:

quote:
Originally posted by DUK:
I'd be interested in getting some loads for 180 and 200 grain bullets.

Did you mean 8X57RS (&JRS)? Have some good ones for that.


Hey DUK!

He's asking about the 8X75RS. Much hotter than the 8X57JS!

This case is made by necking down 9.3X74R brass.

Here's a couple of loads from COTW:

Powder: Alliant RE 22 (I believe you could use Norma MRP1 as a substitute for RE 22) BUT reduce the beginning load 5% from the following to start with, IN EITHER CASE!

180-grain bullet: 71 grains MV 2791 FPS
200 grain bullet: 68 grains MV 2713 FPS

I note that the German factory loading for the "S" version used a 198-grain bullet at 3050 FPS, with a ME of 4120 ft/lb. You MIGHT be able to work up to this velocity with a 200-grain bullet, but it might take IMR 7828, RE 25, Norma MRP2, or a similar burning rate powder instead of RE 22, to do it.

Sorry I have no more data for this round. (I believe this to be a superb cartridge. A double rifle in this caliber would be a real treasure!) Good luck - let us know how it goes!

(formerly eldeguello - posts: 5411, plus those new ones noted below.)

Too bad the rimless round isn't still available.

quote:

Originally posted by lawndart:
Too bad the rimless round isn't still available.

Our dear friend from Neumünster makes rifles in this caliber...the rimless version..perhaps brass is available too??

I understand that brass can be made on a lathe from the rimmed version.

quote:

Originally posted by DUK:
I understand that brass can be made on a lathe from the rimmed version.

Yes, I do it all the time for my FGC's:

Hi,
thank's for the information,
I would love to see an original Mauser Magnum 98 rifle chambered for the 8x75 rimless!

Maybe Herrman had one

Where is ALF? He should have tons of information about Mauser 98 chambered for 8x75 rimless

/

Hi ALF,
Nice to have you back.
Can't wait for more information.

/

Oh, there is areal difference between the .30R and the 8x75RS: with 200grs the .30R finished at 2650fps, while the long 8mm reaches 2800fps and with the heavyweights, the .30R is a real looser!

And than why using a yankee caliber, when you can get a 8mm???

quote:

Originally posted by Monastery-Forester:
Oh, there is areal difference between the .30R and the 8x75RS: with 200grs the .30R finished at 2650fps, while the long 8mm reaches 2800fps and with the heavyweights, the .30R is a real looser!

And than why using a yankee caliber, when you can get a 8mm???

quote:

Originally posted by Monastery-Forester:
Oh, there is areal difference between the .30R and the 8x75RS: with 200grs the .30R finished at 2650fps, while the long 8mm reaches 2800fps and with the heavyweights, the .30R is a real looser!

And than why using a yankee caliber, when you can get a 8mm???

/

quote:

Originally posted by ALF:
Ah yes, the 8x75 R will beat out the 30 R Blaser but just exactly how many 8x75's do you see commercially around today?

The other point is that both these were primarily made for Kipplauf type rifles and thus are relatively low pressure rounds.

Well, it seems to me you could put it in a Ruger No. 1, and load it to its' full potential!

quote:

Originally posted by jens poulsen:
The 8x75 is a fine cartridge either in rimmed or rimless!.
Would love to have a doublerifle in that caliber!


http://www.jww.de/r30/vc_content/bilder/firma445/Archiv...aden_jww_02_0205.pdf

Heym also makes double rifles in 8x75RS.

Not only Heym,also Blaser, Krieghoff, Merkel and the austrians from Ferlach offer the long 8mm in their doubles!

quote:

Originally posted by cewe:
Sounds like it´s no match for the 8x68S but maybe pressures are lower?

Cant compare the 8x68S with the 8x75 (R).

The 8x68S is a Magnum that outperforms both easily!

quote:

Originally posted by ALF:
The CIP pressure spec on the R case is around 3300 bar ( @ around 850 m/s on a 12 gram bullet )

plus minus 47,800 psi / 2700 fps /185 gr bullet ( maximum )

Current CIP max average pressure is 3800 BAR (55,114 PSI) for the 8X75RS.

quote:

Ah yes, the 8x75 R will beat out the 30 R Blaser but just exactly how many 8x75's do you see commercially around today?

More than I see in 30R. As noted, many European makers are chambering the 8X75RS in doubles and singles.

quote:

The other point is that both these were primarily made for Kipplauf type rifles and thus are relatively low pressure rounds.

Even at 250 BAR lower pressure than the 30R (3800 vs 4050) the 8X75RS still easily beats the 30R. Also, the 8 is based on the 9.3X74R case, which the 30R is not, so brass will always be simple.
----------------------------------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

When talking about 8x75 rimmed, I checked C.I.P. standard and the only one listed there is 8 x 75 RS https://bobp.cip-bobp.org/uplo...biical-en-page42.pdf . Now, one thing I do not like on that design; very short neck, just 5,54 mm long. As far as I know, preferable neck length in rifles should be one bullet dia. In this particular case, since brass is 74,60 mm long, I do not see any issue if case neck is 8,5 mm to 9 mm. With this length, case grip on bullet should be much better and powder space loss is negligible.


BTW, I was curious what is in C.I.P. available for 338 using formed 9,3x74 R case, and the only one listed is 8,5 x 75 R Scheiring https://bobp.cip-bobp.org/uplo...5-r-scheiring-en.pdf . This one is even more awkward design; still very short neck, 6,2 mm long, but very steep "Junction cone", 80°. if I remembered correctly, the only way to get such steep angle is fireforming. In this particular case, I would rather see more moderate cone, max. 60°, better 50°, or 40°31'33" like on 7x65 R. These could be done using just dies, no fireforming required.

In that respect, Keith's 338-74 R looks to me as way better designed cartridge https://loaddata.com/Cartridge/338-74-Keith/1560 , but that is another topic.