With military ammo and no magnification, 4 in. at 100 isn't that bad. Just for starters some good handloads or Black Hills match will probably cut it in half. If you use a pistol bullseye target and good iron sights, you should be capable of getting 1.5 in. groups at 100 with good ammo from a rock solid bench rest. There is a heck of a difference in ammo, my varmint barreled AR is a solid 1/2 in. rifle with match ammo, won't shoot better than 1.5- 2 in. with most military type ammo, or Rem 55 FMJ.