Yes Sir DWM . It was called the 25 Souper ...a 308 Winchester necked to 25 with no other changes according to Mr. P.O. Ackley . Some very old numbers give an 87 gr. Bullet 3400 FPS and 100 gr. Bulet 3150 FPS. Believe it or not , Winchester made ONE Pre-64 Model 70 in 25 Souper . I had it in my hands and saw the factory Letter documenting it .....and let it get away ! Not one of my better decisions !
Yes there is such a thing, but its a wildcat. Its basically a 308 necked down to .257 with no other changes. I have one on a Mauser 98 with a 22" Ashton barrel. I dont have dies or even know if its headspaced or not. I haven't shot it or anything. I just wanted it for the action pretty much, and I like .257" caliber. I just dont know if its worth making something out of it. It would be a pretty nice carry rifle though.