Add another label or some super glue!! Maybe you're not getting your ring screws tight enough, most ring mfrs recommend 25 in/lbs, which is more than most would think it is by feel, it's pretty tight when using a screwdriver type tool, not much when you have some leverage on it tho. I put the Nikon Pro-staff on the 500 S&W in lapped Leupold QRWs and used the labels in the bottom rings, they've held up to a bunch of heavy loads including the 700gr Ranger Rick bullets at over 1400fps.
Tim
Blue,
I agree with Tim. I don't mean to belittle you problems. I really do know how frustrating it can be. I have fixed these and many more "problems" for guys with guns for years and years. Here is a bit of back ground on me, I have worked in the firearms industry for more than half my life.(Almost 25yrs) I have been to armours school for the 1911 pistol, the Glock pistol and the 870 rem shotgun. I am an NRA instructor in shotgun and pistol. I am classified a NRA master in 22 bullseye pistol and an NRA expert in center-fire pistol. I have shot countless perfect scores on the trap fields, with all but the 410. I have shot in IPSC and IDPA matches. I have many awards from the old Chevy Truck Challenge matches. I don't mean to blow my own horn here. I just want you to know I am not just blowing smoke. I have been there and done that.
I have mounted countless thousands of scopes on my own and my customers rifles, pistols, shotguns and muzzle-loaders. If I have learned anything, I have learned the hard way that you just cannot skimp on some things. I really like these PRW rings from Leupold. (I think you are using the rifleman series of ring) I have PRW's or QRW's on every center-fire rifle that has a scope and a weaver base on it. I shoot some heavy calibers and never had a hint of one moving. Not a single one has anything between the ring and the tube of the scope. Burris ZEE rings are another popular model and they are also very good. i just prefer the PRW's.
Years back I had some issues with a Contender 357Herrett. I had three rings and still had issues. That was the mid-late 80's when those alum. Bushnell thin rings where the style....(crap really) I went to the BURRIS ZEE ring (Only two) and EPOXIED and re-drilled, tapped for larger screws,(#8) the base on the barrel. I actually sheared off the #6 screws holding the base on the barrel!!! Problems with scope movement and base issues where GONE.
I use one PRW on two of my Bullseye pistols. It hold zero and doesn't move a fraction year after year.
Is your scope tube damaged from old mounting? If not I really think the PRW's will solve your problems.
PM me if you like, I would really like to help you get thru this problem.
CW