7383 in 8X57mm Jword loads

[singleshotbuff]

Gentlemen,

I have been experimenting with surplus IMR-7383 in 7.5X55 and 7.62X54R with good results.

Now I'd like to try it in my 8X57mm with 200gr Jword bullets. Does anyone have data for this? Should I use IMR-4350 starting loads?

All input is appreciated.

SSB

[Ricochet]

Yep. That's probably all that'll fit, anyway.

[singleshotbuff]

Gentlemen,

Tested my first load with IMR-7383 in the 8X57mm today. With 200gr Jword bullets, my Nosler manual indicates a starting charge of IMR-4350 at 46grs. unfortunately, 46grs of 7383 would be VERY compressed, which of course is not a good idea. I wound up starting at 42.0grs, and I do have some room to work up before I get compression.

8X57mm
Winchester case
Federal Magnum primer
42.0grs IMR-7383
198gr FMJ BT
no crimp

ave. velocity: 2053 f.p.s.
s.d.:13.0
e.s.: 38

Slow, and accuracy was a bit disappointing, about 2" for 5 shots at 50 yards from sandbags. I know the gun and bullet are capable of much better than this. I'll keep at it.

I'll try 43 & 44grs this weekend, if the weather holds.

SSB

[Ricochet]

You'll run out of space before hitting service-load velocities or pressures. Don't compress 7383 much, it doesn't like it. Too much breaking of powder kernels.