Personally I lap every set of rings that I get. I see no point is unnecessarily risking damage to my expensive optics out of laziness or being cheap. So my suggestion is this:

I don't care where I got the rings or how much I paid for them, I'm still going to lap them.

....am i seeing things, or are that a ring mark just to the left of the red oval ?

I lap, it's cheap easy insurance.

If you've got a high-quality one-piece base, and high-quality rings, then lapping makes absolutely no sense.

If you've got a high-quality one-piece base, and high-quality rings, then lapping makes absolutely no sense.

a procedure just done to not mar the scope body?

Now don't take this out of context here, because it's just a question from someone who's never lapped rings, but has anyone ever seen an improvement after lapping rings? I'm talking a good set of rings. If so, what was the improvement? Groups get better? Zero wander, or scope slip before lapping? Or is it a procedure just done to not mar the scope body?

Its often not the base and rings thats the problem, its the reciever they get mounted to.

Its often not the base and rings thats the problem, its the reciever they get mounted to.

How is that possible? If the base won't fit right to the receiver, how would lapping the rings help you out?

If using a 1 piece base, you should check to see if it sits on the receiver without and rocking. If the front is not in the same plane, when you torque the base it will stress the scope. If so you should bed the base and lap the rings. This should help alleviate stress placed on the scope body and provide a more secure grip.

Anyone who owns a NF read you manual. Bet it says something about lapping.

Most production rifle actions or ring and base combinations are not manufactured accurately enough to ensure proper alignment out of the box. After properly securing bases and rings to the action, alignment and compression of the rings is required prior to mounting the riflescope. To fulfill this requirement a 30mm lapping bar kit is available from Nightforce or other suppliers of precision shooting products. This lapping bar kit consists of a steel bar 30mm in diameter with a handle attached and a nonimbedding lapping compound. This tool is used to remove unnecessary material from the lower halves of the rings eliminating misalignment. This procedure allows both rings to align with one another, thus creating a stress-free platform for the riflescope.
Step One
With bases and lower halves of the rings securely mounted to the rifle, mount the 30mm steel lapping bar and tighten top ring
halves. This procedure will cause the rings to compress and take set to the lapping bar instead of the tube body of the riflescope.
Do not use the riflescope in place of the steel lapping bar.
Step Two
Remove the lapping bar and apply lapping compound to the lower ring halves. Perform lapping procedure until a maximum of 75% of
the surface area has been lapped of the lower ring halves. (Note: or until the bar moves freely. i.e. no binding halves.)
Step Three
Remove the lapping bar and clean all surfaces with alcohol or other solvent to ensure an oil free surface.