The .257 Wby. has a 1 in 10 twist and won't shoot Nosler 100 gr. ballistic tip bullets very well because of the boattail. This bullet requires a 1 in 9 twist. The 115, 117, and 120, it should shoot good. Berger makes a 115 grn. VLD matchgrade bullet that likes a 1 in 10 twist rate also.Midway...