7x57 from .308

[KY Ratshooter]

With the stretching, pulling swagging and extruding that goes on in a full length resizing die, is it possible for me to form 7x57 cases from .308 brass? 

I am not looking for target accuracy or max pressure loads, just usable brass for cast lead bullet loads.

[deltecs]

It might be possible, but I wouldn't try it.  The neck length on the .308 is already short and would be further shortened by lengthening the shoulder to 7x57 dimensions for headspace control.  The neck length would be extremely minimal at less than 1/8" or very close to .120".  The cost of 7x57 brass is not that expensive compared to potential trouble with this cartridge conversion.  The brass stretching to 7x57 dimensions may be enough to severely weaken it and cause head separation or worse due the thin brass walls.  I would forget this idea.