Rod,
I feel your pain. A while back I had a barrel that shot okay, then I borescoped it... it had what looked like burnt and broken asphalt going down the tops of the lands, on a barrel that couldn't possibly be burnt out. A lot of work with various abrasive solutions (including VFG pellets), and I finally got that crap out of there.
The good news was that that barrel really did shoot better being cleaned down to bare metal like that, every day (~70rds) (this was a match barrel on one of my F-class guns). Going two days... it wasn't happy. Three days... *I* wasn't happy.
The bad news was that it got *real* squirrelly that first couple shots out of the barrel after being cleaned down to bare metal. Like several MOA away from the expected POA/POI. The velocities of those first few shots were extremely erratic, usually quite low - presumably due to the extra friction.
The 'solution' turned out to be something I'd picked up from some BR guys I used to shoot with, a product called '
Smooth-Kote'. If I recall correctly, it's supposed to be "deactivated moly", and essentially what you do is you squirt some on patch or two, and swab the bore with it. The moly should off-gas after a few rounds, but in the interim, it gives you just enough lubrication to normalize things in the barrel... until those first couple shots burn it off, and deposit a little carbon of their own. So no more weird first few shots, and the velocities were right on target with subsequent shots.
HTH,
Monte