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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thats just a standard weaver rail you can pick them up anywhere and they just screw into your scope holes on the receiver. From there you grab some rings and a red dot
I'll have to see if my 'smith can make something up to mount on the side of the Rossi or use the dovetail on the barrel like it appears they have done here.