In answer to your questions about lapping.... New barrels (factory variety, not custom made) come with very small imperfections in the rifling cuts. The small imperfections are like microscopic burrs, if you will, that literally tear the copper from the jacket as the bullet passes over them. Custom barrels are hand lapped before they are shipped, and so these imperfections have been removed, probably by hand lapping. The Tubbs system uses grit impregnated bullets that you load yourself and shoot them normally. The grit grinds away these imperfections as the bullet goes down the barrel. The trouble is, some say too much is ground away, especially in the throat area of the barrel. hand lapping does the same thing except it requires considerably more "elbow grease". I use a jag that is 1 size smaller than the barrel I am working with so that limited pressure is brought to bear on the barrel. I load up a patch with #800 lapping compound, and run it through the barrel back and forth for about 200 strokes (changing the patch and reloading it with compound every 50 strokes). Then I clean the barrel thoroughly with Kroil and Break Free to remove any remaining grit from the compound. Then I dry patch the barrel about 3-4 times. Then I start all over again, except this time I run the patch in one direction only (down) for about 200 laps, this time changing the patch after every 10 laps. After that I go the Kroil, Break Free, and dry patch route described above until the patch comes out clean. Next I load a patch (regular size jag this time) with Flitz metal polish and run that through 15-20 times, and clean the barrel again as above. I finish with a light coating of KG-2 gun oil for storage.
That's about it. It seems like a long process, but it really doesn't take all that much time. I do this to every new barrel I get. I can't say that accuracy is improved significantly, although I believe it is, but the barrel doesn't foul as quickly allowing me to shoot more shots between cleaning.
This same process occurs over time as you shoot the gun, but it does take a quite a few shots. Now for the "other" schools of thought for you to ponder:
1) Some folks say "Just break in the barrel normally and don't worry about lapping."
2) Some folks say "Lapping is a waste of time because it doesn't really do any good."
3) Some say "Get 'ur done quick with Tubbs." (Of course that is a bit tricky if you don't hand load
4) Still others say "Just take it out of the box and start shooting."
As to your question about moly, I have heard of too many of my friends (actual conversations) that have use moly coating and say that 1) it is near impossible to get out of the barrel, especially is you shoot when the barrel is quite warm. 2) Standard deviations are not as consistent with the moly coated bullets 3) The moly coating "strips off" as you seat the bullet, causing uneven coating.
Now I admit i have not actually tried the moly coated stuff in my own guns, but after the conversations I've had, I've heard enough to know I don't want the stuff in my barrels. Call me old fashioned, or stubborn , or plain stupid if you like, but that's just me. I've heard folks say that moly is the thing of the future and that soon we all we be using it.....maybe but I'm planning on keeping a good supply of copper/copper jacketed stuff to last me. There.....I've said too much already....blast away, guys (pun intended).