Vertical split rings?

[WS6]

The way I understand it, to correctly mount a scope using horizontal split rings, one aligns the scope (rotationally), and then tightens VERY SLIGHTLY each screw all the way around (like lugs on a rim), while using feeler gauges to make sure each gap ends up the same between ring halves, and that everything is 15-17 inch-lb of torque.

The way I understand vertically split rings, is that after aligning the scope rotationally, the bottom screws are tightened to the final 15-17 inch-lb, and then the top screws, and then the bottom and top verified. No feeler gauges in all 4 gaps. Much less issue with keeping the scope "straight" while tightening.

Is my understanding correct? If so, it's really pushing me over to ADM or LaRue's camp for a tube-type (non-keyed mount) optic.

If that is correct, how are the ADM's doing in that role? I have read online (yeah, yeah...) of them shooting loose sometimes, of them requiring multiple tightness adjustments (loosening up after the first range trip), and all sorts of things. I also know that the LaRue, if adjusted tight enough will displace a slight amount of anodizing on the rail, causing dimensional change. The clamping area is also much smaller.

I wish Bobro made a vertical split ring mount, but since they don't...which is the better of the LaRue/ADM? Who uses ADM? Didn't they get a SCAR contract or something? Did it go through? Does anyone really in the door-kicking world use ADM, or are they mainly sold to 3-gunners and typical guys like me who might shoot a class or two a year?

I prefer to keep emotions, and "I hate..." "I love..." "So and so sponsors me..." out of this and just go with technical feel-goods and not emotional feel-goods. FWIW, I have a personal history of dislike with Mark LaRue. Fine. But if his gear is the better choice, I'll buy it from one of his distributors that I do like. Well and good. Emotions < Getting the best tool for the job.

[markm]

I'd just go by the manufacturer's recommendation. I Warne (I think) rings where you tighten the one side all the way down and the gap is only on the other side.

[Hochsitz]

I once swapped out a friend's scope on his 300 Win Mag that used vertical split rings on a Weaver rail. When I loosened one ring the entire scope was suddenly loose on the rail. Upon further examination, one of the split rings was tight on the scope but loose on the rail meaning it was doing nothing to support the scope, on a 300 win mag! I learned that day that yes, tightening the bottom screw first is critical.

Now let's consider the LaRue vertical split. It has the same issue plus one. Ask yourself what is the ring aligning to when you tighten those bottom screws? With the previously mentioned Weaver style there is a wedge effect that the tighter you go, the more the ring grabs the rail with zero clearance for movement. Conversely on the LaRue version you have two smooth holes in the base that are filled with threaded bosses, one from each ring half. It's common knowledge that with a 4" ring spacing, just .001" of play corresponds to roughly an inch at 100 yards. Unless those bosses are a PERFECT fit in the base, there is going to be some slop there. I haven't personally examined the ADM mount but it looks to use the same design. Sure, there's some friction generated as the ring pinches the vertical lug of the mount base, but I prefer to stick with the horizontally split rings and eliminate any chance of movement altogether.

As far as installing horizontal split rings goes, an even gap is really just aesthetics. I've seen plenty of guys just close the gap on one side then tighten the other (no attention to detail) but their rifles seem to print groups just as good as the next guy that took 5x as long to assemble his mount just perfectly.