Makes me wonder why they even bothered making dies for the 6.5-.257. As far as I know, they are still available. That pretty much makes it a "Standard wildcat".
I have the reamer and dies, I asked about the price of 6.5mm50 ammo once, after that I was shooting 6.5/257 Roberts. I have one box of RWS 6.5mm57 ammo. I could only guess it was designed for good shots, it came with 5 rounds to the box.
F. Guffey