Does anyone still apply lapping compound to their scope rings, or is that a practice made obsolete by modern production techniques? Or do some brands or rings still benefit from the process?

I never did. Maybe I should have, but I never liked the idea of paying for something that wasn’t sufficiently applicable as is.

I think lapping is a very good idea in many instances. The more parts there are to a mounting system, the better an idea lapping is IMO. I'm sure that some of the premium mounting systems are fine just the way they are out of the box, assuming a corresponding level of precision in the dimensions of the action they go on.

Pic rail and corresponding quality rings I have never done it.

Badger Ordnance used to have a disclaimer that if you lapped their rings, you void the warranty. And that they don't need to be lapped.

And then there's...

https://www.area419.com/product/match-scope-rings/

I do, but don't go full retard on them. It pains me to see nice scopes with bite marks or dents where very poorly aligned rings were bull hunched. The line up bars are handy to get close, then a quick lap.

This is ridiculous! Unfortunately I long ago fell into the 419 trap and will likely find some of these in my mailbox soon.

When lapping rings, you're actually correcting poor screw alignment of the action as much as anything. Hill Country rifles told me, when they were building my 7mag, they lapped 9 out of every 10 rings (mostly Talley's) they put on their trued Rem actions.

Yep, if I was to put something on a Remington action I would assume 9 of 10 times I would have to square it.

Exactly.

Go to a better action, and it's not needed.

Pull the barrel off a Rem 700 and see how they squared the face of the action. With a belt grinder, no exaggeration. A cheap Harbor Freight lathe can get the face of the action more square than that.

I wonder if the new Remington is doing a better job?

I bet they are.

Surely they have learned the lessons they should have learned 30 years ago. And the reasons they went bankrupt.

I lap all mine but I cant remember one in a long time that showed afterwords that it really needed it

I have and do for 1in and 30mm scopes but never bought a 34mm lapping bar. I have noticed uneven lapping on lower and mid tier rings but nothing high end rings seemed very even/consistent.

I think you also didn't get the memo that ring screws do not need 80 in/lbs

Precision rifles and long range glass. I lap those. AR's and closer range hunting stuff not worth the trouble. Not sure if it truly makes a difference though.