Why not just get some 06' brass and neck down, or .270 brass and neck up? Way cheaper and easier. I've taken .308 brass and necked it down to 7mm-08 out of necessity with no problem, something to consider anyway.
Done that plenty of times and it worked just fine. Had to watch my neck thickness on occasions when necking down with thick brass like Remington....basically I had minimal to zero problems though.
