I ordered a barrel from Tim North and he had exactly what I wanted in stock. #4 contour 8 1/2 twist. This is the prefered twist right now. It "hot-rods" a little better than the 1:8. With a 1:8 twist (I used to shoot 1000yd BR) you would ALMOST always see best accuracy at 3000-3050 fps. With a 1:8.5 you can easily find best results at 3100-3150. I don't know why, but this seems to be the case. If you build a 6.5-06 imp the 8.5 twist is even more important.
The 1:8.5 will easily stabilize the 142 SMK and the 140 Berger VLD. I mostly use the 130 Normas these days. Hope this helps
