Is the 8x57mm Mauser(not rimmed) .323 or .318? I have seen it listed as both.

Thanks

The 8x57 J uses a .318" bullet. The 8x57 JS uses the .323" bullet. The 8x57 J was adopted by Germany as their standard miltary round in 1888. In 1905 the diameter was increased to .323" If you are not sure what you have, slug the bore. Not good to shoot big bullets thru small tube.

quote:

Originally posted by craigster:
The 8x57 J uses a .318" bullet. The 8x57 JS uses the .323" bullet. The 8x57 J was adopted by Germany as their standard miltary round in 1888. In 1905 the diameter was increased to .323" If you are not sure what you have, slug the bore. Not good to shoot big bullets thru small tube.

Excellent reply. Right on.

I might add that occasionally you will see them referred to with the letter "I" instead of "J".

All .323 "8mm" calibers should correctly have the "S" added to their designation. So 8x57IS (vs. 8x57I), 8x64S (vs 8x64), 8x68S (no .318 cal equivalent - thankfully) etc etc. This is a crap system, and God only knows how the Germans came up with this idea - but, hey, it has only been that way for 100 years or so now...

In Central Europe, at least the 8x57IS factory ammo is loaded with black primers to make people aware of the difference to the 8x57I...

It is also correct that both the designations "J" and "I" are used for the 8x57IS a.k.a. 8x57JS... I have actually only seen "J"s in headstamps, and people here in Central Europe refer to the cartridge as 8x57IS. Presumably the J/I stands for "Infanterie" - signifying the military past of this excellent little cartridge.

- mike

Everyone has this pretty well covered above but I thought I would add:

8x57J - rimless, .318" bore diameter (aka 8x57I)
8x57JR - rimmed, .318" bore diameter (aka 8x57IR)
8x57JS - rimless, .323" bore diameter (aka 8x57IS; commonly called the "8mm Mauser")
8x57JRS - rimmed, .323" bore diameter (aka 8x57IRS)

-Bob F.