Re: 20 or 40 MOA
I had the 1" rings with a 27 moa base. In the process of switching to a different ring/base. ;)
I had a 40 moa base in the shop, and put it on. That gave me roughly a 750 yard zero with my combination. All my rifles have a 100 yard zero, so this rifle was no different than the rest. I calculated where I needed to be to get my 100 yard zero, and still stay on the bottom of the scope. Then I made a 27 moa base. That gave me my 100 yard zero and still afforded me roughly 55 moa of useable space with the 8x32 NXS.
The 5.5x22 NXS has 100 moa, so all things being equal, that 27 moa base will give you your 100 yard zero and still afford you roughly 90 moa of useable space. The only difference is that you are giving up 10X, which is significant when you get way out there.
You will be close to a 100 yard zero with a 30 moa base.
Remember, you always want to operate in the optical center of the scope.
If I confused you, give me a call you have my number...
