Re: 308 build barrel questions.
most barrels Kreieger, Bartlien, etc are all going to be great barrels.
Length? Well that is kind of up to you. anything between 20" and 24" will be the average. For every inch you cut off the barrel you should see a drop of 30 - 50 fps/inch.
Definitely want a 1:10" twist. 1:11 is fine and so is the 1:12.
People will tell you that all you can run out of a 1:12 twist barrel are 180 gr bullets or less. The faster your twist is the heavier the bullet you can run. Well this is some what true. It really is determined by the length of the bullet not the weight. The longer the bullet is the faster you are going to have to spin it. Of course longer bullets, in general, weigh more. But in the terms of twist rate it is not about the weight of the bullet, it has more to do with the length of the bullet. It is better to over spin a bullet than to under spin it. So, if it were my barrel and I was going to use it for what you are intending on its use, I would opt for the 24", 1:10" twist.
With all that said, you are still going to have to find the round and recipe that your gun likes. My Surgeon likes the Berger 175 OTM's. I am running a 24" Krieger and I am getting 2728 fps. My groups are sub 1/2 MOA.
One other item. The 1:10" twist will allow you to run the longest of 30cal bullets that are on the market today.
HS-Precision I personally would not opt for. Great stock, don't get me wrong here. It is that their customer service leaves something to be desired. Bell & Carlson, McMillan, Manners, Accuracy International is the way that I'd go. More money? Yes. But their service after the sale is second to none.
Please understand, HS-Precisions are great stocks and will serve you well. I am just sharing some of my experiences with them and what I have seen from other people who have bought their stocks.