240gr Flying good?

[bigdaa250]

I have a friend that finally went to a 1/7 twist barrel to get his subsonic 240gr bullets flying good from his 16" barrel. I have not been able to find ayone that makes 1/7 twist .308 barrels. I am in the market for a 300 whisper upper, kit, or components and I would like to know if anyone else is getting the 240gr bullets to fly good subsonic with a 1/8 twist barrel? Not interested in the other bullet configurations, I have other uppers if I want to go fast.

Thanks