i built a 25 Creedmoor/ Brux barrel 7 1/2 twist i call a 257 Creedmoor i posted a lot of information about this fine cartridge on 24 campfire in the long range forum . i used all 3 bigger 25 caliber bullets >131 gr. Black jacks , 128 Hammer bullets and the 135 gr. Berger bullets . i also had custom dies made by Whidden for the 257 Creedmoor too and that made a big difference in accuracy , price was not that bad on the dies either.
i also built 2 - 257 Roberts /7 1/2 twist for hunting both shoot excellent. i ordered a Brux barrel ,#4 contour ,7 1/2 twist , will be finished at 28 inches and chambered in a 257 Weatherby mag. and put on a Weatherby mag. mark 5 action should be a great long range rifle for hunting probably use the 128 gr. Hammer bullets , hope too make close to 3400 fps ? Twolf