Ruger Standard rear sight slipping

I have a 1969 Ruger Standard semi auto 22 in like new condition. After being kept clean and dry in storage for 35+ years, I have started shooting it again.

The rear sight, after 60-70 rounds are fired has started to creep to the left, causing the point of impact to move left as well. It is a fixed sight, inserted into a dovetail.

Upon first discovering this, I tapped it back in place but it simply moves again with more shooting.

FYI - Ruger will recondition for $35 plus parts. But with $73 to ship to them (I am in a 'remote' area) and a $30 return fee, it isn't worth it.

Any suggested fixes with any kind of Loctite or other? Best fro a gunsmith to do it?

Many thanks...

I've read of people using locktight and/or using a center punch to put a raised dimple on the underside of the sight to raise it in the dovetail ever so slightly. You would also want to besure to use something to clean any oil/lube that might be in the dovetail allowing the sight to slip.

I would drill and tap the sight if possible to receive a small set screw. This will make it very solid and not move and you will still be able to remove the sight later if you wan to up grade. A prime example is the rear sight of the Ruger P90. It is in 45 cal and is rock solid tight when the set screw is tight and has a small amount of lock tight on it. Just make sure you don't use the permentent stuff or you will never be able to remove your sight.

Maybe the simplest "fix" involves using a brass punch and light hammer taps to push the lips (that is, the "overhang") of the female dovetail slot down a little, tightening it.
Remove the rear sight, tap the slot's lips down, and then carefully replace the sight using that brass punch and the hammer.
The lips don't have to move much, so don't overdo it.