This is my 50mm Obj. scope, 30mm ADM-Recon w/20 moa & Buttler Creek scope caps, as you can see there's not much clearence left if you're going to use scope caps. ADM says they're 1.470 ( I assume that's correct) http://www.americandefensemanufacturing.com/view/product/298/ Primary Arms shows 1.403 (Type o ?) https://www.primaryarms.com/American_Defense_ADRECON_30MM_20_MOA_Moun_p/ad-recon-30-20moa.htm if you plan to use scope caps don't forget to factor them into your clearance.