I just received my ARMS BUIS and my ARMS #22M68 with the cantilever extension.  Now for my question - I've read in several places concerning where to use the loctite and I'm a bit confused.  The BUIS came with loctite, and I assume it's to use on the screw that tighten it to the rail.  Is there anywhere else I need to use the loctite?  Thanks.

btt

Here is where I use BLUE loctite.... and many will consider this overboard.... but it works for me:

First, I use gunscrubber, brake parts cleaner, or alcohol on the mount, and all the mounting screws, to remove the shipping oil covering everything.

When assembling the spacer to the lower mount, I add a drop or two of loctite on the groove of the spacer, to stiffen the contact between mount and spacer.  Do the same between spacer and upper mount.  Then loctite on each mounting mounting screw... just a drop on the tip of the threads, and tighten.

Then, a drop on the 4 ring mounting screws that hold the aimpoint in the ring.

On the buis, I put loctite on both ends of the threaded bar that holds the BUIS to the flat-top, then assemble, and tighten.

Done.  Nothing will move, or back out.... but you can take it apart later when needed.