About what speeds could I expect shooting 140 grain bullets and what powders would be good for this round? I want something new to play with. More then likely I'll be using 7X57 cases and a mauser action.

Cartridges Of the Worold has

140 grain bullet, 43.5 grains of IMR4350 yeilding a velocity of 2700 fps.
If you have minimum info and you are begging to load the 6.5X57 using starting loads from 6.5x55 might be prudent. They really are pretty close as far as case capacity. roger

I could be wrong but I think Seafire is probably the most knowledgable about the 6.5x57.

http://forums.accuratereloadin...=profile&u=446105161

Alan

As Roger Said...you can use 6.5 x 55 data pretty interchangably if it is an older Mauser action..

if it is a Modern Higher pressure action, then you can use 260 Remington data...

as always, work up...with heavier bullets on a long action, you can better a 260s velocity, but then again, remember that most 6.5 bore bullets perform best at about 2800 to 2900 fps MV... due to most being designed for the older 6.5 bores from the turn of the last century....

for what it is worth... I prefer to use either Win 257 Roberts +P cases or Win 6mm Rem case and neck up...

VERY INTERESTING!!!! roger