with my Savage 116 in 7mm-08. Shooting just 50 yards with Rem core lokts 140 grain the first 2 groups is always 3 - 4 inches. After that my groups tighten up to 2 inches roughly at 100yds.
That group size at 100 yards is acceptable providing your using remington factory ammo.
Try some different ammo Hornady or Federal would come to mind
2 questions: when you shoot do you let the barrel cool and if so for how long? How are you cleaning your barrel and are you leaving oil in the bore prior to shooting ?