You might want to look towards the 1-9 twist for your project especially if your going to go with the high B.C VLD bullets such as the the A-Max 162,Berger 168,180 or the Cauterucio VLD.
I'm having a 7mm WSM built on a Rem700 long action right now, I went with the long action so I can shoot the heavier VLD's in a repeater.All the guy's I know who have built long range 7mm WSM's have gone with a 1-9 several are shooting Mike Rock barrels. I'm running a 30" Shilen heavy palma and my good friend is shooting a Obermyer heavy palma contour all in a 9 twist.
Mine is on a Model 700 long action.
Badger Ord bolt knob
8/40 base screws
Badger Ord pinned recoil lug
Shilen 1-9 SS select/match 30" heavy palma
Vais Arms brake threaded 5/8-24 to fit a suppressor
Chambered in 7mm WSM with the lead diameter 1 thou over groove for the 180gr Cauterucio VLD's they have a B.C, of .875!!!!!! when pushed just over 3100fps....Incredible.....
God grant me the serenity to accept the things I cannot shoot.The courage to shoot the things I can and the wisdom to dope the wind and make the shot.