Federal Premium, Vital Shok, 20 Gauge, 2.75, TruBall, 5 Round Box PB203RS Forget what you think you know about smoothbore slug gun accuracy. The Federal Premium(R) TruBall(R) is the most consistent smoothbore slug on the market, capable of groups as tight as 1.4 inch at 50 yards. The TruBall system locks the components together centering and pushing the rifled slug out of the barrel. This promotes clean separation of components after muzzle exit to ensure the best accuracy.