Good groups all depend on the ammo you are shooting.
First,if this is a new rifle-Break the barrel in. Savage guns are great shooters out of the box for the most part,but a new barrel should be broke in if you are wanting to get the best accuracy out of it.
Break-In & Cleaning
Lilja Precision Rifle Barrels - Centerfire Maintenance
You will also need to find out just what type of bullets/weights your barrel likes to shoot.If you don't reload,then you'll just have to try different brands/weights of factory ammo,and that can get very expensive-fast.
Most 308's shoot 150-180gr bullets pretty good,no matter the brand,but sometimes you can get one that is very picky about what it shoots good.
A Model 12 Savage should shoot 1 moa or better all day long with the right ammo and a good shooter pulling the trigger.