Correction: Had the rifle been recently fired, the first shot would have removed any rust. However, this shot would not have removed "signs of the effect of wear and corrosion".
This is not a word game. There is a big difference.
However, this shot would not have removed "signs of the effect of wear and corrosion".
Cite please for the first shot not removing the effect of corrosion.
Frazier said that the interior of the surface of the barrel was roughened from corrosion or wear. Pitting is an example of the effects of corrosion; holes in the metal of the inside of the barrel. Holes in the metal would obviously not be removed when the rifle fires off a shot.
It's very important to never state that the inside of the barrel was rusty when examined, for if true it would mean that the rifle did not fire off a shot because if it had, then the rust would have been removed during the process. Since Frazier did not say the barrel was rusty, for a member here to claim the barrel was rusty is irresponsible.
However, again, holes in the metal of the inside of the barrel (the effects of corrosion) would not be affected when the rifle fires off a shot.