While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
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Go 20 MOA from the get go. Only severely limited scopes wont be able to zero at 100yds, if you've got 40 moa or more you shouldn't have any trouble zeroing at 100 and then you've got a lot more to play with when you start reaching out there. Its better than buying twice, trust me