Action base

Lots of things to consider however in general I think 20 suites more peoples needs. Not saying there is not a place for 30 but I think its for a much smaller set of people.
 
My main concern is scope use, if my calculations are correct most good scopes (Razor Gen 2, USO B25, Kahles, Nightforce, etc) should have enough elevation travel to allow to zero at 100 yds w/ 30 MOA base without significant optic distortion. Is that assumption correct?