I too believe I'd stick with the 1/12" This twist has proven quite accurate in the .308. I suppose the 1/14 would be fast enough for bullets not much over the length of that 168-grain. But if you ever wanted to use a 200-grain for longer ranges, you'd be out of luck.

Good luck with your project!

I use 1in10 in all my 30 calibers.

I'm having my (shot out .22-250) Ruger MK II VT rebarreled in .308 Win. I want to build a precision rifle around the Sierra 168 MK. The gunsmith advises a 1-14" twist, while I think a 1-12" would be better. Your advise is welcome.

A 14 twist will indeed stabilize the 168 MK fine. I have seen benchresters use 15 twist for 150 grain FB bullets.

If you are going to shoot the 168 or less, go with the 14.

Go no slower than 1:12" for your 168s. I use 1:10" for most of mine.

Russ

No slower thn 1/12".
1/10" if you intend to ever shoot 180, 190, 0r 200 grain bullets.
JCN
My Sako TRG 22 Sniper rifle has a 1/11" twist.

Yup, it's me, does CB = Gary. I'm cluttering up Saeed's board too...


I'm still thinking 1 x 11 for that 308 and try the 175MKs (BC ~.506) and the 155 Lapua Scenars (BC ~.506) as well as the 168 MKs (BC ~.446).

Andre, don't worry about "over-stabilizing" bullets with a faster twist than you might absolutely need. You get an awful lot of flexibility in exchange. If this was a bench gun, and you were hell-bent on shooting aggregate match results in the .2's, perhaps (but only perhaps) then I would go for the slowest possible twist. But if you are building an informal accuracy rifle based on a Ruger, I doubt you'll see any difference from over-stabilization.

What barrel manufacture are you getting??
- mike

S/S Lothar Walther of course, what else . Thanks for the info, friends. Knowing I really can't go wrong between 1-10" and 1-14" gives me some margin in terms of immediate availablity.

Think also in terms of the maximum distance that you might want to shoot at. The Hunter Benchrest crowd, who shoot light bullets at short (100 - 200 yards/meters) go for the looser twists. Military snipers, who have to deliver their little HPBT tokens of affection much further out go for the tighter twists. As DKing alluded to above, the 175 SMK is a superior bullet. With a 24 - 26" barrel it (and the Laua 155) will get you all the way to 1000 still supersonic.