Re: 257 Wby Mag
Those 3 groove barrels, all five of them, are 1 in 10 twist. We too were stunned with the performance, you are not supposed to get those velocities. We are using Norma brass. My bullet jump is approx. .070". Dan's is .100" don't remember Tim's jump. I have loaded some of the brass up three times and none of the primer pockets have gotten loose, there are no bolt lift issues or other anomilies. Guess all things came together.
The most amazing rifle is Dan's lightweight rifle. He had a model 700 action lightened as much as possible, #3 SS fluted, cut at 24" in an edge stock with a 3.5-10 x 40 VX III with an M1 turret. He has killed 4 elk and three mule deer bucks in Co. He says he doesn't know why he has all his other rifles, because this is his go to rifle. He shot his muley this year on the run at 200 yds. The little VLD went through the lower part of both shoulders and exited. Velocity for this rig is approx 3550.
One of my friends used my 28" #5 profile with a turreted 4.5-14 x 40 VX III on our coues wt hunt. He had never been able to shoot very far with his rigs. He and I were together and I watched him take a small buck at exactly 400 yds, his longest shot ever. The shot was a perfect setup, broadside feeding on the fruit of a barrel cactus. He twisted up 2 MOA, prone with a bi-pod made the shot. My tripod mounted 15X binos trained on the deer allowed me to see bullet hit just behind the shoulder, the blood squirted outwards towards us, and the deer fell right there never to move again. It was as if a switch was thrown. Turns out the bullet was very close to the spine and I think that turned off the deer's system. Exit was 1" dia. Very impressive.