Questions on my scope mount bedding job

[Dr. Vette]

Before I try my first bedding job on a recoil lug I thought I'd start small and try bedding a scope base to an action. I used JB Weld because it's cheap and easy, and seems to be used often. I do have Devcon but am saving that for "real" bedding jobs.

This rifle was obtained with the scope base already installed. I removed it and noted on test fitting it that the rear portion of the base had a slight "gap" between the base and the receiver when the front base screws were tightened. So, I thought that I'd bed it, using the front two screws to provide most of the pressure and allowing the JB Weld to fill the gap in the rear.


Release agent applied to the receiver, the mount was cleaned, degreased and prepped, JB applied to the mount and the mount was installed by tightening the front 2 screws until they started to "grab." The rear screw was then tightened until it met resistance and I stopped.

See photos below. I'm a bit stumped that 1) the metal of the base appears to not have ever touched the receiver though "almost" did at the location of the arrow, and 2) some of the JB flaked off despite very thorough preparation (I paint parts I restore for Corvettes so I'm not new to prep work). The JB that did not stick to the scope base easily removed from the receiver using my fingernail.

Should the front two screws have been tightened further to squeeze out more JB Weld? Should I roughen up the scope base further so that the JB adheres better? Or should I not have removed the base from the receiver to check my work?

Thanks for any feedback you may have.

Front of base:




Rear of base:

 

[Dr. Vette]

Just for information....

I redid the bedding. First scraped off the JB, then taped up the mount and bead blasted the bottom metal that actually mates with the receiver so that the next attempt would bond well.

I then applied new JB to the mount and reinstalled it but made 2 changes. The front screws were torqued to spec at 25 in-lbs and the rear screw was not used at all. I took a nail of the correct dimension, placed tape on it about an inch from the end, and used the nail to fill the rear hole as well as properly align the rear mount. So, the rear of the mount was allowed to "float" so that the mount isn't stressed at all in the rear. After a couple of hours I removed the nail and threaded the rear screw in and out to make sure the threads in the receiver were clear.

I'm not removing it now. I'll just have to assume it looks fine underneath.