I have a 12 fvss. and installed an EGW 20moa base on it. i used Burris low tactical rings on that base with a 30mm scope tube and a 44mm objective lense (the big end) lol it fit about right. theres about a 1/4" under the scope but if i were you, and you are planning on puttin a aftermarket stock on it or you want to (be able to shoot) long range later you can. Just make sure your scope has enough elevation travel to zero at a the closer ranges with a 20moa base with all things being perfect you'll need at least 20 down to zero it at 100yards. just my .02 tho hope this helps