Mounting a Weaver Base

[Ascot500]

I want to attach a Weaver base to a Marlin .22 barrel that is not drilled and tapped
How can I pick the best base since Weaver does not show what diameter cylinder the bottom of the base fits
And, I want to use adhesive instead of drilling and tapping - any recommendation?

 

[Kp321]

Don’t have my Weaver chart close by but the bases for a Winchester 62 should work. They should fit the barrel contour closely. If not, wrap some 80 grit sandpaper around the barrel and run the base back and forth over it till the contours match. Leave the base rough and degrease the barrel before attaching with Acraglas, JB Weld, or Loctite 380(Black Max).