I'm preparing to make a lot of 8x50R Austrian (sometimes I've seen it as 8x50 Steyr) ammo for a couple M95 rifles in what I believe to be their original chambering (i.e. they do not have an "S" or "H" stamped over the chamber). I found a nice used die set at a gunshow years ago and I believe that the 7.62x54R case can simply be necked up to hold the 0.323" bullet, and that worked easily for a couple trial cases I played with last night.
Do I really need to trim the cases back to 50 mm, or will they still be safe at 54mm? One person in the archives of this forum suggested it is safe to leave the longer length, but I want more opinions. I expect fire-forming will also shorten the case, judging by the larger curves on the 8x50R neck vs. the sharp shoulders on the 7.62x54R case. I bought a charger block of original 1890 dated ammo for comparison purposes and those cases measured 50.5 mm, so I will use that as the trim to length if trimming is needed.
The same original 1890 ammo also seems to have bullets closer to 0.318" diameter (like the early German 8x57J round!) than the standard 0.323". At least that is their diameter just outside the case neck. Is that what they are supposed to be? I know the later 8x56R Hungarian uses larger 0.329'/0.330" bullets, but I thought the original 8x50R rifles' ammo used "standard" 0.323" bullets. What's the historical truth? Both my 8x50R rifles are WWI-era, so did the Austrians follow the Germans and start with 0.318" bullets/barrels then switch to 0.323" bullets/barrels before the Great War? Should I be slugging my bores just to be sure?
Powder will be IMR4895 under a 200 grain round nose Sierra or Hornady bullet. I will start with lighter loads based on 7.62x54R charges, aiming for about 80% of the case volume to be filled.
All comments and advice welcome!