8mm Improved

30 June 2001, 09:08

Stonecreek

Interesting combination which I don't think I've ever run across. If I understand correctly, you have a barrel with an 8mm (.323) bore, and a chamber that fits a .30-40 Krag case, but with straightend walls and sharpened shoulder. Is this right?

If so, it should be similar in capacity to the 8 x 56, and chamber pressures for the 8 x 56 should also be acceptable in the '95 Winchester.

So if it was mine, I'd use 8 x 56 data as a rough guide.

Low pressure 8 x 57 data reduced 10% would also put you in the ball park.

08 July 2001, 07:04

carcano91

quote:
Originally posted by magua:
Just found a barrel for my Win 1895 in 8mm Improved based on the 30-40 krag case. Does anybody have any reloading info or cautions.

Now that's an interesting, if somewhat whimsical wildcat. The dimensions seem roughly comparable to the German 8 x 57 IR(S) and the Danish 8 x 58 R Krag, but powder space would be quite a bit less. A bit smaller is the 8 x 57 R 360.

I believe that for starters, 8 x 57 IR minimum data with 10 % reduction could be used. These are already pretty conservative. However, the old 8 x 57 R 360 is even smaller dimensionally, and thus its data may be preferable.

IMPORTANT HINT:
The 8 x 57 R 360 reacts very tempermentally to fast powders; even small loads increases or seating depth differences may cause significant pressure jumps (source: DEVA handbook, 4th edition and RWS handbook, 8th ed.). Given the similar case shape, the same phenomenon might occur with your "8mm US Krag improved", when using faster powders, so take care.

Best regards,
Alexander Eichener
carcano91@hotmail.com

26 July 2001, 01:07

<magua>

Thanks for the help gentlemen. I haven't had the barrel installed yet as I'm waiting for another rifle to be finished but you have given me a start. I will let you know how it works out in a few months and until then blast away.