hey there,
i have a savage action that always gives me the same problem no matter what barrel i put on it, what scope i put on it, etc... it always puts me at the top half of my scope adjustment when i have the particular round i am shooting at the time zeroed at 300yrds...
i have always had 20moa nightforce 2 piece bases on this action and when my 308 barrel is on said action and i am using my zeiss 3-9 (66moa total elevation available)
shooting to 1030yrds (needs 36 moa from my zero to make it there) i was always finding myself about 6moa or so short....
i basically went through all the stuff everyone here has been recomending to you and ruled every thing out and came to the conclusion that i had an action that is either slightly warped or the machining of the top of the receiver is not flush and has a taper or step making it high in the front causing about 30 moa of reverse cant....
if there is a step or the receiver is warped making the front mounting point higher then needed, there shoud be a noticeable gap between the base and the receiver at the back mounting point if you just have the front mount screws screwed in... if that is the case you could glass-bed the back of the mount to fill the gap and that should get you back to 20 moa correction in your mount (this will also help reduce any torquing in the scope mount and scope when you tighten down the rear screws)
if there is an actual reverse taper in the action then you are probably gonna want to get a more aggressive scope mount to correct for it... 40 moa should get you there...
since i have 2 piece bases i corrected my problem by just shimming the rear scope mount with pieces of a beer can (i know i'm cheap
) and let my burris z-ring inserts copensate and prevent torquing the scope... i didnt have any z-ring offset inserts at the time but thats another route i could have gone to fix my problem....
anyways.... just saying if you run through all the other good advice everyone else is giving you and you still have the problem then it could just be an out of speck action...
orch