I try a box of each of the following ammo in my tactical rifles: Federal Match, Remington Match, Winchester Match, Lapua (from HIRSCH PRECISION), Norma Diamondline and Hornady Match to see what is closest to the optimum loading for that rifle. Hornady is by far the best factory ammo across the board with all my rifles, that I have used. It is consistantly tight in every rifle I have.
Each rifle likes one ammo a bit more than others, my AT rifles love the Norma and are good with the Hornady but not too good with anything else. The Hornady is tight in everything and I am very impressed by it. It is much less expensive than the Federal Match and is Moly coated. It goes for a little over $20 US per 20 rnds stateside in most shops and I have a wholesale source that is just over $17. Federal match is over $37 CAN... plus tax here in town!
I'm going to try Ruag for the first time myself soon and am trying to get my hands on some Lake City ammo as well.
There's a nice comparison of .308 match ammo on the Sniper Central web site.
Try some Hornady, along with everything else and then try some handloads of your own. I have received different load data from other shooters that duplicate their favoritte factoy loads with great success and reloading is fun way to pass the time during the winter. Have a friend who knows what he's doing show you the ropes when you start, will save you lots of time and grief.
X2 Awesome advice 
