Lapping and Polishing barrels

My guess would be that they don't do it for the same reason that most PB makers don't ...It takes time and time =money ..
My direct supervisor at the factory where I work told me his biggest challenge is figuring the balance between cost and quality . We manufacture AC condensing units and if there were a real life place for it we could make one that would outlive either of us , but the cost would be so high that no one would buy it .
The returns for lapping a barrel for a " serious" airgunner I personally think are worth it , but if you added another say 15$ to the average 100$ break barrel you wouldn't make your target price . And would the design itself have enough inherent accuracy that you would see the difference anyway ? Probably not .
But a gun like the RAW with much more time spent on material and fitting and quality can take the time to make it like they want . Much smaller targeted customer who demands the best accuracy possible .
As far as wearing unevenly I guess its possible ? But I lap all the guns I rebuild and its never honestly entered my mind .
 
I have a question. Is checking to a drill the accepted way? I only ask because a Marauder tuner, Greg Davis does his by hand ....7 or so passes back and forth with a brush wrapped with abrasive soaked paper towel then change the towel with fresh. Repeat 6 or so times so total strokes, around 45-50

Also you don't let the abrasive end come out of the crown right?

Just want to do the best way.

Thanks

K