Gunsmithing Need advice on fixing loose mount screws

[Flint62a1]

I have a Mosin PE sniper mount and for some reason the screws on the mount itself come loose after about 20 rounds. I'm pretty sure the threads were not done all that well to begin with so I'm stuck with it. I have tried the blue(breakable) loktite and it's not working. The was I see it I have 2 options. The first being red loktite. I realize that stuff requires a good amount of heat to break it loose. I don't see this mount ever being removed from the rifle. It's on there to stay. The other option I was considering was to devcon the screws in place. Maybe even devcon the mount to the reciever? What are your thoughts?
Devcon? JB Weld?
Thanks for any help you lend here, Kevin

 

[Arc Light]

If blue loctite isn't holding, I doubt red will either. Blue should have more than enough holding power for small screws like that. One of the main reasons thread lockers don't hold is because the surfaces are not thoroughly degreased first. I would use acetone on the screws and female threads if you haven't already and try the loctite again.

 

[Flint62a1]

If blue loctite isn't holding, I doubt red will either. Blue should have more than enough holding power for small screws like that. One of the main reasons thread lockers don't hold is because the surfaces are not thoroughly degreased first. I would use acetone on the screws and female threads if you haven't already and try the loctite again.

Thanks I'll try the acetone, I had degreased them with alcohol, acetone would be better. Should have realized that. Would you recommend going right to the red? If that doesn't hold I guess I'll have to jb weld them.

I just saw theres a gap between the mount and reciever, and that should not be there. So it makes sense that the mount breaks loose like it does. So I'm going to have to shim the mount then redo the screws.
I'm wondering if a layer of JB weld would work?
Thanks, Kevin

 

[aprocast]

Alcohol isn’t a degreaser, an epoxy like jb will be better than an anaerobic adhesive in this case because it is a better gap filler

 

[Arc Light]

As stated, alcohol is not a very good degreaser, especially not the common stuff available at your local pharmacy or Walmart.

I would thoroughly degrease all surfaces with acetone or brake cleaner, let them dry thoroughly, then try the blue again. If that doesn't hold, jb weld would be a good (nearly permanent) option.

 

[Wannashootit]

Someone boogered up that repro...
Agree with the epoxy solution if the threads weren't correctly drilled and tapped.
Probably done by someone with a cordless drill and wallowed out the holes.

A bit of judicious heat with a torch will allow removal if you ever need to remove it.

 

[want2learn]

it would be a bit more work but after assuring that the surfaces are congruent you could change out the current screw and bore pattern to a slightly larger outer dimension screw

 

[RTH1800]

Have LRI bump it out to 8x40.

 

[Flint62a1]

Have LRI bump it out to 8x40.

LRI???

 

[RTH1800]

Long rifles incorporated

 

[Wannashootit]

Those are probably #10 (doubt it's metric), definitely not on the small side.
ive only messed with a couple of those; most require shimming the back of the base to align the centerline of the scope with the bore.