how do i use swivel flush cup to anchor one side of rail i want to install on a-5 stock

[baredog]

i want to install rail on my stock or two threaded holes to put on front bag rider . I have one threaded hole by unscrewing swivel..The other area is a swivel flush mount hole....thanks Barry

 

[Clancy]

I’d just add a 3rd hole behind the flush cup if it’s below flush and use the long atlas rail.

 

[baredog]

yea could do that just thought someplace made something where i could use that flush cup...thanks for response.