I took my .338 lapua out the other day to shoot and I ran out of elevation at a little over 900 yards. It's built on a cz 550 magnum action. Anyway to get a 20 moa base on it without drilling into my action? I know Ken ferral makes a base for a cz 550 but it looks like it has holes in the top of them. Also heard the Burris made z rings with 20 moa inserts but can't find any.