Obsolete cartridges

[MS 9x56]

I seem to have a penchant for buying rifles chambered in obsolete and nearly unobtainable ammunition. My newest acquisition is a ma user 98 proofed in 1937 in 8mm mauser. Just my luck is turns out it is chambered in 8x57 J. Bore diameter .318. It is a gorgeous engraved rifle with raised rib full length, 1/2 octagon 1/2 round barrel wearing a Lyman peep sight mounted on the bolt release lever. Just an awsome custom sporting ma user 98. Already ordered dies but where do I find load information?

 

[93marlin]

If I remember correctly, there's an issue of Cartridges of the World has separate loadings for the 318 bullet.
I'll check and see if I can find my copy.
I currently have three 8x57 sporters.
All with the S bore. Awesome caliber!

 

[93marlin]

Well, it wasn't in Cartridges of the World.
Ken Waters "Pet Loads" is where I read about the 318 bullet in the 8x57.
All that was said make sure of the diameter of your rifle.
Start with some reasonable loads well below the maximum listed.
The 8x57 is a great cartridge! Enjoy your sporter!
Post some photos if you get the chance.

 

[Zinz]

I’ll be watching this thread. I also have a beautiful Sporter with a J bore

 

[steve white]

I would be surprised if there is any significant difference between J and JS loading data unless exceptions are made for older weaker actions/condition. Loading data for other than the original 196gr. bullets may be more scarce for the .318 version, as well. Any data for American 8x57 Mauser lighter bullets will almost certainly suffice, since loads are kept consistently mild to prevent .323 projectiles from being fired in .318 bores. Someone may prove me wrong, but I am basing it off formulations for 8x57JR in European brands. 318 diameter bullets can be gotten from many sources. I have Woodleigh, and Hawk in just the bullets, and in rimmed version, loaded ammo from S&B, RWS, and Norma, which as mentioned are loaded hotter than American brands in .323 diameter rounds.
Norma probably has brass, as well, even if it is new old stock. You can certainly neck size downward with 8x57JS brass, but headstamps will then be wrong.
Surely there will be information listed online just by typing in 8x57J, from various sources.
Yamoon and other 8x57 fans will surely chime in soon.
I would have jumped on the rifle you purchased myself, if it was affordable! Sounds like a peach.