Which VLD in 9 twist 6.5WSM?

[sambo3006]

My 6.5WSM 9 twist Lilja doesn't seem to shoot 129 gr SST's any better than 1 moa. My local gun shop has some 130 and 140 gr VLD's. The 140 box says use 9 twist or faster. Would I be safer trying the 130's? They still have a super BC at .595 as compared to the 140 at .640 BC. What say you guys?

[davewilson]

140 or 142's

[sambo3006]

Thanks, Dave.
Any other input? Surely some more of you guys are shooting these 6.5mm VLD's?!?

[River Man]

I have a ballistic stability calculation program in an Excel spreadsheet that I downloaded years ago. I can't verify the authenticity of the program but it appears to give reasonable answers.

To calculate bullet stabiilty you need to know bullet (projectile) length, bullet weight, barrel twist rate, and bullet speed. The program will then calculate whether or not the bullet will be marginally stable, fully stable, or maximally stabalized. You can call the bullet manufacturer and ask for the bullet length if you don't own a box. The length of the bullets needs to be meausured to the nearest 0.001 inches in most cases especially if you are close to one of the stability limits.

If you want I can email you a copy of the program.

Dennis