I'm having difficulties mounting a scope onto my Savage Mk. 2 G .22 rifle. It is a pre accu-trigger and is not drilled and tapped for mounts. I believe it has a dovetail (groove running down the middle of the receiver on top, I'm not too experienced with scope mounting terms) to mount the rings to.

Anyway, I tried mounting a set of Weaver brand 1" medium rings to it (using a 3-9x40mm scope w/ 1" tube). The rings are supposed to fit a 3/8" grooved receiver. After I snugged the rings down (pretty tightly) and fired a few shots the rings had basically slid all the way back and off of the dovetail. Is there a special trick to secure these things down or did I just get the wrong rings? It seems like there is nothing to hold the rings securely in position to prevent such slippage.

I've mounted a few scopes before and never ran into this problem. I would prefer not having to take this to a gunsmith.

Please help! Thank you!!