I am placing a 1 inch tube Swarvoski 3x9-36 on my AR .308 Carbine. The specs on the scope says the total adjustability is 58" at 100 yards. How does this convert into mils? I need 7-8 mils to reach 700 yards and I need to know if I need to go with a canted 10 or 20 MOA mount. I also believe this 58" adjustment is total so do I half this amount since the upper adjustment does you not good. I'm a newbie so please help.