Re: 308 Barrel Twist How to Decide
The problem is that you can't have your cake and eat it too. While technically, you can run 110gr to 200gr bullets in the .308, doing it all with a single barrel is not ideal, nor will you likely get great results across the range of bullets weights you are thinking of using.
If you want to shoot as light as 110gr, I don't think that either barrel twist option you are considering is "ideal." You'd be better suited with a 1:12 twist for those purposes, but by doing so, you narrow your ability to stabilize the heavier pills. You would probably be better served with a 1:11.25 twist rather than the tighter 1:10 if you are primarily running up to 175gr bullets. Your mileage may vary in terms of performance with the heavier, 190gr+ bullets which is where the 1:10 begins to shine. I have switched to 1:10 twists in almost all my 308s, but I am only running as light as 155gr bullets (and as heavy as 208gr).
Frankly, I agree with BCP re: "varmint" bullets in a .308...I see no need whatsoever to run anything lighter than 150gr bullets from a 308. If you want a varmint gun, buy a varmint gun...but I will tell you, varmints get dead just as well and just as easy with 155gr bullets as they do with the lighter pills (TRUST ME...I've been doing it for years with an AR-10 or a .308 bolt gun when an AR-15 wasn't handy)!!