Slipping Scope

[MagMan]

Beat up a nice Swarovski on a 300 RUM because of it.

 

[Bravo 4]

My .338 RUM had to have a third ring, the scope slipped no matter what I did. Now I have a slightly lighter scope and placed the bubble level in front of the rear ring and torqued it to the same specs as the scope rings. Hoping maybe that will serve in somewhat manner as a third ring/parking brake, at least maybe a scope slip zero stop.

 

[Snyper708]

The purpose of lapping is to remove mis-alignment in the rings. If the rings are manufactured a might to large a diameter it is possible to lap out any squeeze they have on the scope.

That's probably what happened.

The rings are made to fit a certain size, so lapping is only going to make them bigger. It's easy to over do things, trying to make them "better".

I'd forget about the Loctite and the lapping and just put the parts together.

It works for the vast majority of set-ups.

 

[FEENIX]

If things don't work out for you I'll give you an option that always works for me which is the Burris Signature rings with the plastic inserts that auto align the scope meaning you don't need to lap rings. I also stick a piece of golf grip tape under the top inserts (so the inserts are stuck to the scope). I've never had a scope slide with this setup and I've got 15 long guns with most of them setup this way.

+1! The XTRs are built like a tank and provides an additional 40 MOA of adjustment.

 

[7stw]

Sounds to me like you over lapped the rings allowing the scope to slip.

You may have to replace the rings, because as stated, the scope should not move from the recoil of a 7mm mag.

Buy a top end set of rings and bases (The weaver style has smaller cross pins and more slack, allowing for more misalignment) and reaming will not be necessary to prevent slipping and marking the scope.

Just My opinion

J E CUSTOM

I'll second JE' s thoughts on that. I believe you honed away the grip on your rings. You can get carried away with that quite easily. On weaver type , or picatinny rails, I like the LEUPOLD rings. The cross slot fits the groove rather snuggly, and haven't had isdues with slippage either.
Years ago, I used to use, almost exclusively, Leupolds dual dove tail rings and bases. They align great, don't slip. One caveat is if you have mis drilled receiver , you can't adjust it out. But then again, you can't with pic rails, or weaver bases either. Just some thoughts and options.

 

[7stw]

Beat up a nice Swarovski on a 300 RUM because of it.

Ouch

 

[johnnyk]

Years ago, I used to use, almost exclusively, Leupolds dual dove tail rings and bases. They align great, don't slip.

Me too! Back then I vowed to never go to the Picatinny type rail. I used the Leupold Std (windage screws) too and they actually made a LR base for Remington 700's (20MOA) and Win 70's (10MOA). Those bases with the Burris Signature STD rings allowed you to add serious MOA and maintain sleek lines.
As a matter of fact, I have one setting on my desk right now. I recently traded a pistol for a 1st generation Sendero in .300 WinMag which had a STD LR base on it.
You know Nightforce doesn't recommend (under no circumstances) these turn-in style rotary/dovetail-type ring and base designs(especially those equipped with windage adjustment) and says so on page 8 of their ATACR/NXS owners manual. Not sure I buy that.
I know this is off topic a bit but I had to bust out! LoL. Johnnyk.

 

[J E Custom]

Sand bag(s).
I believe I may have over torqued the cross bolts because I used the "dry threads" number with Loctite.
Hopefully, I will make it to the range early next week.

Here are some recommended torque values that May help.

https://www.longrangehunting.com/threads/torque-recomendations.29756/

These are based on the screw size and the material.

J E CUSTOM

 

[Konrad]

That's probably what happened.

The rings are made to fit a certain size, so lapping is only going to make them bigger. It's easy to over do things, trying to make them "better".

I'd forget about the Loctite and the lapping and just put the parts together.

It works for the vast majority of set-ups.

There is still plenty of space between the top clamp and the bottom half of the ring. I don't believe I over -lapped the rings.

 

[Konrad]

Here are some recommended torque values that May help.

https://www.longrangehunting.com/threads/torque-recomendations.29756/

These are based on the screw size and the material.

J E CUSTOM

Back, long ago (yes, we had electricity then) I attended a class on fasteners that included proper torqueing techniques for bolts of many types. One fact often overlooked by folks is the listed torque values in most sources are for dry threads. Most thread engagement rarely goes over 75%. Adding a "lubricant" of any type (including thread locking compound) should lower the torque value by at least 10%.
Also, the tensile testing machine during that class revealed that if a fastener is torqued properly and then loosened, it's tensile strength (the point at which the fastener shears) is reduced by at least 25% on the next tightening cycle.
I replace scope mounting threaded hardware parts each time they are loosened.

 

[mjkten]

I read an article on this site just today where Jim See bedded the scope into the rings. He used release agent on the scope tube and J.B. Weld as the bedding into the ring itself.
I have also read an article by Ross Seyfried where he used some sort of electrical insulating liquid rubber compound in the rings to lock the scope in place on particularly hard recoiling rifles.

 

[hunterdan]

I have had great success with the Rosin.

 

[Barrelnut]

I have had great success with the Rosin.

Some are in the know. I won't setup rings without it anymore.