I copied this from
www.Pac-nor.comThese are barrels made in various twists and Groove configurations:
30 (.308")
2 groove 16"
3 groove 6.50" 7" 7.50" 9" 10" 12" 13" 14" 15"
4 groove 10" 11"
5 groove 4" 7" 8" 9" 10" 11" 12" 13" 15" 17" 18"
6 groove 8" 14"
Polygonal 8" 10" 12"
Match the bullet weight(length)with the twist rate you want to shoot, then ask the barrel maker what is "right" for you...they know their business.
Most people will never shoot over 180g in an '06, and a 12" twist will handle all the Hunting bullets in 180g with the excepton of some specialized target bullets. There are some long VLD Match 180's that may require a faster twist.
The following is copied from
www.berger.com (Berger Bullets)
30 CALIBER
30 cal 155 Grain Match Hunting VLD 0.308 155 0.439 0.225 14
30 cal 168 Grain Match Hunting VLD 0.308 168 0.473 0.242 13
30 cal 175 Grain Match Hunting VLD 0.308 175 0.498 0.255 13
30 cal 185 Grain Match Hunting VLD 0.308 185 0.549 0.281 12
30 cal 190 Grain Match Hunting VLD 0.308 190 0.570 0.291 12
30 cal 210 Grain Match Hunting VLD 0.308 210 0.631 0.323 11
the last number in the column is Twist required to stabalize that particular bullet. These are long VLD bullets that require a little more twist to stabalize them. As you can see, even the longest and heaviest bullet only needs a 11" twist.
Some years ago, I had a 308 made with a 14" twist and it was a fantastic shooter with 125,150, and 165g hunting bullets. This rifle shot so well, I have yet to see another Bolt gun shoot this well in 308, I'm talking very tiny groups. It was not a question as to whether or not the bullets would go in a hole, but how large the hole was. It was a #5 taper, 24" long. I ended up shooting the 150g Hornady in it at 3025 fps, (slower twist builds a little less pressure + perhaps a fast barrel using Win 748).
