Going to have have another 308 built, will shoot 168 and 175 weights exclusively, what twist barrel would be best?
1 in 10 twist, second choice 1 in 9.
J E CUSTOM
For 168's and 175's? I would think a 1:12 would be plenty, but your the chief of the .308 tribe!
Tank
BAD IDEA.
There's an old saying in highpower shooting. "Friends don't let friends use 168s (Sierras) at 1000 yards." The 168 Sierra (and the post-1980 180s) are dynamically unstable in flight, and go unstable around Mach 1. We're talking about bullets flying through targets at large yaw angles, (90+ degrees to the line of flight), and highly erratic ballistics. Oh, you can make a 168 Sierra work at 1000 yards - if you can fire it at an MV of 2700+ FPS. There's a notorious load known as "G4" or "G8" that was a long time 1000 yard load using the 168 Sierra. The secret behind this load? 44+ grains of IMR-4895 in a Lake City casing.
Sorry JE but 168s have never ever been used "successfully" at 1000 by anyone on a routine basis in a 308! That is just a cold hard fact that is undisputable.
You must be thinking of 600 which is the place that they have been used very successfully or possibly a few Garand (30-06) shooters that were able to use it sometimes succesfully..
In fact the 168 was designed for 300 meter matches in 1958 and is normally too short to keep stable at 1000 out of most 308 guns.
I have spent too much time in the pits at 1k watching keyholing bullets of anyone that tried to take the 168s at 1k in a 308.
All of the Sierra techs will tell you the same thing.
There is a very good reason why they ARE NOT shot today by anyone successfully at 1000. The dominant 308 round for 1k is one of the 155s, 175 or even the 185/190 Berger in Fclass today. You will never ever see the 168 on the line with a shooter that is not a newbie and then only once as they learn.
all you really have to do is go to the Long Range Target shooting forum where all the top 308 shooters hang out and do a little reading
Asa Yam is one of the best: here is his comments on the 168 SMK in a 308
BH