8x57 JR 8x57 JRS 8x57 JS

30 May 2011, 23:57

bpesteve

More 8mm lore - "Usually", and I say this with some waffling, 8mm _German_ cartridges having no "S" in their name, like the 8x58R Sauer, 8x72R, 8x60, 8x75 &etc are nominally .318". Many of these have .323" brothers, like the 8x60S and 8x75S. There were a few _German_ 8mms that have only ever been .323" like the 8x68S. Note that even this example, the 8x68S, has the S moniker even though as far as I know it was never commercially offered in the smaller diameter.

_Non-German_ 8mms, on the other hand, are almost always (I'm not certain about the 8x58R Danish and there are no doubt other exceptions) at least .323", many being even a bit larger. These include the 8x56 Mannlicher-Schoenauer, 8x50R Mannlicher, 8x56R Mannlicher, 8x50R Lebel, 8mm Rem Mag and a slew of early transitional military cartridges like the Murata, Guedes and Kropatchek.

Lots of comments to follow,I hope.

31 May 2011, 00:24

Alberta Canuck

quote:
Originally posted by bpesteve:
More 8mm lore - "Usually", and I say this with some waffling, 8mm _German_ cartridges having no "S" in their name, like the 8x58R Sauer, 8x72R, 8x60, 8x75 &etc are nominally .318". Many of these have .323" brothers, like the 8x60S and 8x75S. There were a few _German_ 8mms that have only ever been .323" like the 8x68S. Note that even this example, the 8x68S, has the S moniker even though as far as I know it was never commercially offered in the smaller diameter.

_Non-German_ 8mms, on the other hand, are almost always (I'm not certain about the 8x58R Danish and there are no doubt other exceptions) at least .323", many being even a bit larger. These include the 8x56 Mannlicher-Schoenauer, 8x50R Mannlicher, 8x56R Mannlicher, 8x50R Lebel, 8mm Rem Mag and a slew of early transitional military cartridges like the Murata, Guedes and Kropatchek.

Lots of comments to follow,I hope.

Yes, some of the non-German 8 mms are quite a bit larger than .323"- - - the most common in the U.S. at this time probably being surplus 8x56-R straight-pull military Mannlicher bolt action rifles & carbines. Their bullet diameter is commonly right around .330" +/- .001". Bullets are available from Graf's, amongst others.

P.S: .... some of those military straight-pull Mannlichers were manufactured in the standard German 8x57 rimless Mauser and .323" groove diameters, when the Germans were occupying Austria and Hungary.

31 May 2011, 04:50

enfieldspares

To add to the confusion....we British had 7.92mm BESA...which was standard 8x57mm!

31 May 2011, 06:36

SR4759

quote:
Originally posted by enfieldspares:
To add to the confusion....we British had 7.92mm BESA...which was standard 8x57mm!

Must have been confusing for Bren gunners and MG -26 crews too...

31 May 2011, 19:06

white bison

Thanks. All for the valued info.

Best Regards,

Tom

31 May 2011, 21:27

Stonecreek

While you didn't ask, I know owners of "J"-bores who regularly shoot .323" bullets without ill effect. A conventional lead core/jacketed bullet will swage down a few one-thousandths without too much protest, either in the form of pressure or accuracy. However, if I were doing it, I would start my loads on the light side.

I was offered an 8x60 Sako once and considered it, but I was not totally comfortable with either searching for .318" bullets or trying to use .323" bullets in it.

03 June 2011, 07:05

SR4759

If you research the so called .318 bores such as the GEW 88's you will find that they are not really not .318. They will actually measure .320 to .321.
Passing up a rifle for the lack of .318 bullets can be a mistake if the bore is large enough to shoot the .321 bullets designed for the .32 Special. Hornady even has a .321 flextip for those that can't live without pointy bullets.

For the doubters check out old threads at the Gunboards. There is a collector/accumulator there that has data on over 100 GEW 88 barrels that he has checked.

09 June 2011, 06:29

Idaho Sharpshooter

SR,

I just bought a C.G.Haenel on the 88 action. I am not sure if it is a 1900 or the rarer 1909. It has .315" stamped crookedly on the left side of the 28" tapered octagon barrel. This would be the earlier of the two designated 8x57mm's correct?

Thanks,

Rich

09 June 2011, 08:19

J.D.Steele

Rich, you might try making a bore cast or slugging the bore. I've measured several of these early 1888s as well as several 1908 8x56 Mannlicher-Schoenauers and found their actual groove diameters to be in the 0.327"-0.328" range.
Regards, Joe

10 June 2011, 03:54

xausa

quote:
Originally posted by Stonecreek:
While you didn't ask, I know owners of "J"-bores who regularly shoot .323" bullets without ill effect. A conventional lead core/jacketed bullet will swage down a few one-thousandths without too much protest, either in the form of pressure or accuracy. .

The problem with shooting a bullet larger than groove diameter through a rifle barrel is not in the diameter of the bullet, but in the amount of neck clearance in the cartridge. If a bullet will go into the neck of a fired case with little or no resistance, then it will be safe to fire in the rifle.

This can be critical where the same cartridge uses different bullet sizes in different rifles. My original Mannlicher Schoenauer in 6.5X54 uses .268" diameter bullets, while my custom barreled Greek Mannlicher actioned rifle in the same caliber uses .264" bullets. Fortunately, the cartridges loaded with the larger bullets will not chamber in the rifle using the smaller diameter bullets.

Firing a cartridge in a chamber with inadequate neck clearance can have disasterous effects.