01-21-2020, 02:37 PM
Quality parts? probably not, I do agree with your friend at least in part. The purpose of lapping is to remove any high-spots or imperfections on the circular mating edge of the upper, not to grind down the entire surface some amount of mils. With any mechanical process there is always a possibility of one or more imperfections left on the surface. Removing that high spot should not endanger any anodizing. Further, the lapping only is to improve on that one, narrow circular edge ("top" of the upper against which the barrel flange rests) therefore all anodizing on all other surfaces will not be touched.
I don't know how deep the anodizing treatment goes down into the metal, but IMO a bit of lapping should not remove all of it.
You get a couple of things when you get a good quality upper rcvr: concentricity, bore-alignment, tight-fitting to the barrel extension, excellent mil-spec dimensional adherence, etc.
Lapping will not make a poor upper a good one, it can make a good one really good... properly done.
If yours didn't need it you're gtg. Some of mine did and some didn't. I'm happy with all of mine.
I don't know how deep the anodizing treatment goes down into the metal, but IMO a bit of lapping should not remove all of it.
You get a couple of things when you get a good quality upper rcvr: concentricity, bore-alignment, tight-fitting to the barrel extension, excellent mil-spec dimensional adherence, etc.
Lapping will not make a poor upper a good one, it can make a good one really good... properly done.
If yours didn't need it you're gtg. Some of mine did and some didn't. I'm happy with all of mine.
"Down the floor, out the door, Go Brandon Go!!!!!"