In looking at the Vanguard versus the A-Bolt Medallion, I believe that they are of equal accuracy, but I would personally take the Vanguard. I believe the Vanguard has the regular loading system, of feeding your rounds down into the magazine from the open action.
Tha A-Bolt has a different system, which I personally can't stand. The floor plate swings down, and then there is a small sheet metal magazine that attaches to the floorplate (and only holds 3 rounds?), that you have to pull off to load, or that you can reload by putting rounds in it while it is hanging on the swinging floorplate. Perhaps I am wrong, and you can also load the magazine by shoving rounds down into the magazine from the top of the open action? But, all in all, I think the system is very cheesey and ruins an otherwise excellent rifle.
Regards,
Mannyrock