I bought a Vortex 1-6x LPVO with the BDC and Vortex 30mm ring mount. The owner's manual for the LPVO indicates to NOT using any thread lock on the rings, which is contrary to anything I've read about mounting optics. Are LPVO's different in that regard and just go with what's indicated in the owner's manual? Thanks - J

It's just not really necessary.

Using thread locking compound lubricates the threads (while wet). If you tighten to the recommended torque, you'll end up over-tightening your mount because the liquid has reduced the friction between threads.  This could impair or even permanently damage your optic.  It's just not worth it.  Buy quality mounts from reputable manufacturers, tighten per the manufacturer's recommendations, and you won't have any issues.

Follow their recommendations.   They know what they are talking about.

The comments above about loctite lubricating the threads and over torqueing are accurate.

If you use Loctite on tiny screws it should be #222. It's not normally available in stores, you'll have to order online from major industrial supply houses. It's purple.

I won't use anything stronger than #222 on scope rings. #242 works fine for slightly larger screws.

There are several things at play, here...

1)coatings matter, as do surface finishes. The smoothness of the anodizing as well as the threads on the screws influence clamping vs rotational force. Blued screws vs stainless matter. It all matters.

2) design matters. The area under the screw head is the source of a lot of rotational drag, influencing clamping force.

3)threads should be lubricated for even clamping loads. Period. Full stop. What you lubricate them with matters. SPUHR uses a wax type compound. It has a very low k factor. Loctite is slightly higher, similar to light machine oil. Some lubricants have a very high k factor, and can really ratchet up clamping force without changing torque required.

4) in the real world, I have seen loctite vs dry screws cause more tube compression. Measured. With feeler gauges. Its "real".

5) is loctite necessary? Loctite is typically used on solid joints. For example, a scope base mounted to a receiver of an m24. The only thing that maintains tension is bolt stretch. This means that any vibration can affect this joint by causing tension fluctuation of the stretched bolt. The action can result in the bolt backing out, as its tension is constantly increased/decreased, allowing it to "walk". With a scope, the screws do not stretch appreciably. The tube compresses and acts as a mechanism supplying tension. Under vibration, the tube can walk (scope slide in rings), ergo, we match ring and scope surface, area, and compression to overcome this in our various applications. However, the scope does not randomly change size, so it cannot "walk" as a stretched screw under vibration, so long as we overcome its propensity to walk under recoil by achieving enough psi at the ring/tube juncture.

What do I do? I personally like loctite. I pick robust scope manufacturers and mounts with torque specs below what the optic company suggests. I also know that most military oriented optics have some leeway in the design. You will not crush a nightforce using 2.7 in-lb more torque than the good manual calls for. To whit, I use nightforce optics and Badger c1 mounts. The optic calls for 25, the mount 20. I then use loctite 243 on this joint and end up somewhere in the neighborhood, and my stuff wont be moving. Also, yes, mount manufacturers also build in allowances. Also, yes, multiple companies test optics and mounts well outside of published norms to assess function when installed...less than optimally.

This said, vortex is sensitive to torque specs. I would indeed follow their guidance. It is the scope tube which compresses, and acts as the tension supplier in this "joint". Scope material, design, and wall thickness are the pertinent factors. The scope manufacturer is in the best place to advise you, on this juncture, for that reason. ARC and similar rings are another topic all together.

I would do as instructed by @VortexOptics.

Got it, thanks for all of the feedback. It's my first LPVO. Thanks!

I bought the Vortex torch wrench, a level for the top of the scope, a level for the side of the rifle, and a vice. Considering I've never done this before I think it came out pretty well. I have a rifle / carbine class tomorrow that I'm taking this too and will zero it during the class, see how it goes.

Just browsing around on the topics in this section, saw the title of your comment. That's interesting you use Loctite #222. I use #242 for front sights on my Glocks (and it works great), but I've never used #222, but I don't know if screws for front sights are considered "tiny" or "slightly larger" All I know is I have great retention with #242. Maybe I'll pick up some #222 and give it a try.
Sorry for the topic derail... I agree the OP should not use any threadlocker on his LPVO mounts.

I put a little bit of blue loctite on screws with a small brush and wait for it to dry out and then mount the rings. Seems to work very well for me and never had anything come loose.

A touch of blue.

It needed with rings. Torque to spec

LaRue mounts the ring screws have dried red thread locker on them.

Use locktite. After a couple 5k run and guns I managed to still finish pretty high with 6 of my 8 scope ring screws loose and all of my holster screws loose, 2 of the 5 fell out. This was the gcode quick release plate that holds the holster to the belt mount. I used a torque wrench per spec and they still loosened up.