And I'll be a mild naysayer to using lapping bullets like the Tubbs system to polish the bore.
Not because they don't work...I know they do and I've seen the results.
I haven't known any guys that have gotten better accuracy after lapping the barrel, but lapped barrels DO foul less quickly than a rough one.
I just can't bring myself to intentionally accelerate the wear on the rifling but using abrasive coated bullets. My thinking is that I'll wear it out soon enough by running regular ammo down the tube.

Someday I may get around to changing my thinking though...