I want the lowest scope mounting possible and I dont know the math or totally familiar on how to go about figuring out if its going to work or not with low rings, or if I need mediums. Rifle is a Rem 700 243 win. Base is a 1 piece Weaver Extended Tactical w/20 MOA Scope is a Vortex Viper 6.5-20x44, 30mm tube. Rings I am looking at are the Weaver 6 screw tactical in either low or medium height. I would love to be able to get away with the lows, but I dont wanna order them to find out they wont clear and have to send them back and get mediums, etc... Thanks in advance.