It seems 257 Roberts brass is hard to come buy and 7x57 brass is also hard to come buy.. does anyone know what case i can make 257 Roberts brass from..I think i can just neck up 6mm Remington cases and fire form them. I can buy factory ammo and shoot it up for the cases. that seems to be a good way to get the brass i want.. I don't anneal , never have.. I was considering getting a annealing machine because others have had great success with them and i was thinking if i shoot up some 257 brass and anneal it i would last me a long time..