168 gn in a 1/14' 308

[johnno]

Hi do I have any chance in shooting a 168gn bullet out of a 1 in 14" twist 308 with any level of accuracy out to 1000 meters.
I know I can do 150gn and such without a problem but I'd like to have something that bucks the wind a little better.

Regards

Johnno

 

[Asa_Yam]

Hi do I have any chance in shooting a 168gn bullet out of a 1 in 14" twist 308 with any level of accuracy out to 1000 meters.

NO.
Not because the twist is insufficient to keep the 168 stable at the muzzle, but rather because there is a dynamic stability problem with most .308 bullets as they approach the speed of sound. With a 168 Sierra, the stability problem appears around Mach 1.2. When fired at 2600 FPS, this is around 900 yards.

Use a 155 grain bullet if you want more mass and a slightly higher ballistic coefficient. If you want to use heavier bullets, you need a 12 twist to ensure 175s and 190s are stable under all conditions down to -40F,which happens to be -40C).

I note from your profile that you are in Queensland. I assume temperatures there will not dip to -40F, so a 1 in 13" twist may suffice for shooting 175s.

 

[aJR]

Johnno, I'm from Nth QLD, match temps never get below 75 f here, just started using 200Smks in a 13 twist @3150fps ..Weathers pretty horrible at present so i don't know how good they can shoot, but i just won the last match of the year at 500,shot small group and high score..Asa is right forget the 168 if you want a bullet to do all the distances, in a small case then it's hard to go past the 155s..JR..Jeff Rogers