I've got a Aero Precision 30mm extended mount for my AR. About to pull the trigger on glass.

The objective on the glass is 50mm. It's straight Pic Rail all the way down from Upper Receiver to MBUS front sight on the other end. Will this mount work or will I need a higher mount?

This should help: http://www.mil-rad.com/scope_ring_calculator

I always buy the tallest I can find for sale when mounting a scope with a large bell. Seems to work out every time. Even on scopes that have smaller bells, it seems I need the added height on an AR or the scope is too low to get behind without straining to get my eye low enough to be in the center of the rear lens. The fixed stock on an AR is higher than a lot of rifles, which traditionally have more drop.

Just in case someone runs across this thread. 50mm objective fits fine on standard height rings.

I use a usually use a 1.5"rail to optics center mount o all my scopes with a 50mm bell. Just to be sure scope and lens caps will clear barrel. you might get away with a 1.35" mount.