Scope on my Sears Model 25 won't stay put.

[BLD]

I've got this old Sears & Roebuck .22 that came with an awful 4x scope & ring set. I went to wally world and bought a Bushnell Sportsman 3-9x40 scope, Ordered a B Square 3/8 dovetail to weaver adapter and some Leupold vertical split rings. While I'm happy with the cheap scope, I am having a problem with the whole setup moving forward during firring. I have the base and rings pretty tight, but don't want to go any further and risk breaking them. The B Square adapters were pretty hard to get on the dovetail rail and yet the little .22lr is able to move them forward almost 1/2" in about 100 rounds. Also the scope moves forward about 1/4 inch in the rings in the same amount of time leaving my scope 1/2-3/4" further from were I want it. None of the screws are coming loose either. They are just as tight as when I set the scope where I wanted it. Does anyone have any suggestions on how to keep my setup were I want it, or do I need to spend another $50 to $80 on my rifle?
Since this rifle was a gift from a family member, and is older than I am I do not want to do anything to permanently change it, like drilling and tapping for a scope mount. I also do not want to spend much, or anymore money on it as all of my money is tied up in holsters, and a .308 bolt gun prject.
Here are some visual aides.





Thanks.

[22popnsplat]

I have used double stick scotch tape on the inside of the scope rings to avoid ring marks and to hold scopes in place , In this case though it sounds like something odd is going on like a mismatch of sizes . If things are tight they should not move . I have not used those paticular rings but maybe the layer of tape will help .
These days whenever I can i use Burris zee signiture rings , have worked the best for me and never need to use tape .

[maxicon]

Dovetails have a problem with sliding sometimes, which is why the Weaver design became more popular.

If the Weaver adapters are single-piece clamps, where tightening them squeezes the clamp closed, rather than tightening a separate clamp against the rail, it often takes pretty good tightening to get them to stay in place. I have better luck with mounts with a separate clamping piece.

The Leupold rings should grip plenty tight, assuming the scope tube's in spec. For vertically split rings, you want to tighten the bottom first, then the top. If it still slides, tighten down a little more.

I'd try giving everything an extra 1/8-1/4 turn and see if it holds. If not, try a different mount.

[BLD]

Thanks. I'll give that a shot. I was a little worried about cranking down to hard because the bases and rings are both aluminum. I have a history of tightening things too tight and either stripping hardware or breaking things. (Mongo Smash!) If that doesn't work I may try the double sided tape.

On a side not my cheap scope seems to work well on this old rifle. I shot a five shot group at less than 1" at 50 yards. If you remove the 1 flyer then it was a .5" group at 50 yards. Not bad for a rifle that sat for 30 years without a proper cleaning (after being shot extensively), and a trigger that's well over 10 lbs.