I own a Remington 700 chambered in .338 Lapua. I just recently got a Night Force Scope. I HAD an aluminum base, but want to go with a Steel Base. Night Force Makes a Steel one-piece base, but they are made in 20 MOA and 40 MOA. My question is, what is the difference and is it even needed? I will very rarely be shooting over 600 yards. I understand that they add those amount of elevation. So does this mean they are designed for really long distance shots? any feedback/advise would be appreciated.