In the past, I have used the lapping bar to hold rings straight while torquing the base, and occasionally lapped the rings enough to smooth high spots, but without fully lapping them for the reasons Evelio cited - plus sloth, of course.

Yesterday I made time to lap a pair of Leupold Rifleman rings and was very surprised at the result, both on the rings and in my attitude toward lapping.

Rifleman rings are Leupold's inexpensive WalMart line that are made of aluminum and have come in handy on weight challenged builds. These smoothed out quickly into a nice, buttery feel, even through the 220 grit lapping compound. These are very soft rings without heat treating that may not stand up to heavy use, so anyone using them on high power rifles has a heads up. This unexpected result of lapping the rings was getting to know them.

Rings I've lapped in the past lost material high and low, sensible because this shows they were designed to provide some clamping pressure as the screws were tightened down. These rings lost material on the sides, around the splits, which seems mindless. Someone else is welcome to explain this one to me, but right now I'm calling it more "get to know your gear" experience and another argument to use something else.

The end result is a very smooth set of rings that apply more even pressure on the scope while I wait for the Talley replacements to arrive. After this experience those will also get lapped, not to compensate for spacers but to proof the rings and smooth out irregularities. Unless you're able and willing to pay someone else to do this, and until the process is automated, ring lapping looks like one of those routine chores we'll need to do for ourselves.

Blaubear, I've had the same experience with the rifleman rings as far as lapping in inexplicable places, I suspect something in the mfg./handling process warps them.
As far as them being unable to handle the recoil of centerfires I've used them on a varity of mild recoiling rifles {7-08,6.5x308} since Leupold introduced them without any problems.

Thanks Kevin! Rifleman rings are inexpensive so, Leupold had to cut corners somewhere and my concern was their ability to stay on zero, but if they can, they can. Sometimes we can invest time and effort to finish an item to a higher standard, such as pillar bedding a rifle, and other times we end up trying to make a silk purse from a sow's ear and it's helpful to know which is which!