the savage 220 has been tested by the savage themselves with Remington Accutips and Federal Vital Shok
I found the Accutips to have the edge on the Vital Shoks, also when it comes to the 20ga I find that the 3" will shoot better then the 2-3/4" once you get to about 100 yards or further
12ga, I will say use the 2-3/4", the 3" is just adding recoil to your shoulder