Re: GDI Scope Mount 25 MOA or 0 MOA??
The elevation adjsutments needed for longer ranges, using 308, are larger than some people know.
I fed the ballistics for my current handload, which closely mimics the ballistics of Federal Gold medal and Black Hilsl Match (so it's a TYPICAL load, not a slow one)into the "Shooter" app on my iPhone.
With a 100 yard zero, the elvation adjsutments needed, for atmospheric conditions that are typical not abnormal are:
500 yards: 14.1 MOA
700 yards: 25.4 MOA
1000 yards: 48.3 MOA
Some scopes, like the Nightforce F1, probably handle that fine. Others won't.
More importantly, why limit yourself? Going to the 25 MOA base STILL allwos you to zero the rifle at 100 yards, while giving you a lot more upside in case you ever need it.
I myself run a Nightforce 56mm Benchrest model with 1/8 clicks that is limited to 40 MOA internally. I run a 20 degree Larue combination mount that holds the scope, mounts to the Picatinny, and includes quick disconnect that really does return to zero every time. I am able to flip it with only a very minor windage adjustment between my LMT 308 and my TRG 338 Lapua. On both rifles, the 100 yard zero is about 3.5 MOA above "bottom", so I have 36.5 MOA left internally, while having the benefits of 1/8 clicks and 42 power. My 338 Lapua TRG needs under 30 MOA at 1000 yards, so I'm covered there. On the 308, I am good to almost 900 yards without using holdover (I DO have 10 MOA holdover as well in the reticle though), which is more than I will shoot that 16" barreled 308 at when I have the Lapua to use instead.
I can't imagine why I would have gone with a zero MOA when my 20 MOA gives me so much more range if I want it.
I'd say go with the 25 MOA base. That extra $150 is a small price to avoid future "I should haves".
Jim G