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Rifle Scopes Zeroing 20MOA base and 20MOA ring mount?

Totoro

Sergeant of the Hide
Full Member
Minuteman
Dec 25, 2019
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433
Gold Country, PRK
Hey fellas, has anyone run into any issues zeroing a 20MOA base with 20MOA ring mount (Spuhr) at 100yds/m?

Considering building a 300NM on Deviant with integral 20MOA rail and adding a 20MOA Spuhr mount to max out elevation travel.

Seem to remember a thread about it but cant remember where I read it.

Thanks!
 
Depends on what scope you are using. Some scopes have more than enough elevation range to zero with 40 moa mount, some don’t.
 
You will need 80 MOA of total vertical elevation travel if (big if) both rings and base are exactly 20 MOA and the base is perfectly aligned with the bore. 90 would would be enough for a margin of error.

Mount rail and rings. Adjust turrets to the midpoint for both elevation and windage, then come down 40 MOA. It should start you on paper.

I did one where I didn't have any margin of error. I ended up zeroing at 200yds. I just hold under 1-1/2 MOA if I need to shoot at 100.
 
I run 45 moa total with my Cronus
If you’re scope has plenty of elevation it’s no issue.
 
What scope is it?

Common practice is to NOT have the scope zero'd out at the very edge of its travel. If you have a scope that has 100MOA or more total adjustment, I would be comfortable running 40 MOA if the rifle capability called for it.
 
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You should have no issues with those optics. I have no problem with zeroing a similar setup with a zco527.
 
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You will need 80 MOA of total vertical elevation travel if (big if) both rings and base are exactly 20 MOA and the base is perfectly aligned with the bore. 90 would would be enough for a margin of error.

Mount rail and rings. Adjust turrets to the midpoint for both elevation and windage, then come down 40 MOA. It should start you on paper.

I did one where I didn't have any margin of error. I ended up zeroing at 200yds. I just hold under 1-1/2 MOA if I need to shoot at 100.

Wrong, bullet drop and scope to bore offset mean you are only about 3 MOA below scope centre with a 20MOA base. A scope with a 50 MOA or 15MIL total elevation range should be fine with 40MOA rail.

The ATACR scopes would zero at 100 yards with 60MOA of cant. I have 40MOA bases to use with 30mm tube scopes and will be using a 6MIL Spuhr on top of a 40MOA rail for my Delta Stryker.