What I did say is that powder residue is left on the bullet (as well as residue in the barrel),
making a positive pairing identification very easy. That isn't ignorance, it's common sense.
I wouldn't think firearms examiners are ballistic experts. That's pretty much what I said.
Yep, there are many variables, including down-range energy, penetration (to name a few
more) that would confuse a firearms examiner. That knowledge would really only be needed
to determine where a shot(s) came from at a long distance. Many of us long-range shooters
use this ballistics knowledge to determine what bullet to use to shoot Bambi.
You see pal, one needs DETECTABLE residue in sufficient amounts, unaltered to the point of being of use in any analytical method. Bullets removed from a victim that are too damaged for a match to the weapon just don’t have that. That’s where your ignorance of the real world shows.
Doc provided a great reference for me on SCIENTIFIC methods for GSR. I’m wading through the hundreds of other citations in that paper. So far, NOTHING supports what you’ve been claiming. When I actually find something, I’ll let you know.