I use Talley bases and rings on my Sakos. The base slides over the integral dovetail, then use any of the Talley rings.
Can't remember off hand which fits the AV

http://www.midwayusa.com/viewproduct/?productnumber=116552
or
http://www.midwayusa.com/viewproduct/?productnumber=196348


Neal
NRA Endowment Life Member.