Interesting, silica won't act as an abrasive or polish steel?
Check the Mohs hardness scale, steel rates a 5, silica a 7, diamond a 10.
Yep the silica is blown into the rifling, much on the bottom.
Operative word...rifling...twist, remember?
So the silica ends up on the surface of the bullet,
mixed in the lube, spinning down the bore,
leaving lube and silica coating on all the rifling, right?
So silica will polish the bore, but it takes time.
Not like hand lapping by a skilled technician,
but still smooths the imperfections.
I know, mouthy, contentious, old coot.
no...simply uninformed amateur.
you ever borescope a rimfire barrel with 10,000,20,000, 30,000 rounds down the pipe? No polishing.
used to be pitting......no polishing.