>I love it when the crime scene people can tell the cartridge from the wound. "Looks he was shot with a nine!"

Again, I "understand" the fiction shows are a joke, but I don't understand why the shows telling about real crimes can't be more accurate and why they are getting less and less accurate.

Crime show scenes I have seen are:
Longmire: It's a large wound, had to be a .45, long range shot, had to be a .45-70, accurate shot, well, there are no modern .45-70s so it had to be an old Sharpes sniper rifle, go check out anyone who bought an old Sharps in the last year.
Some unknown shows: that bullet' is too small to be a .38, so it is 9mm. Looks like it was fired from a Glock...
That's a .38. Must have been fired by a cop...
CSI: I ran the metal through the FTIR and determined the alloy. Note: FTIR does infrared analysis and works mostly on organic material. You would use X-ray fluorescence, usually as part of an electron microscope, for metal analysis (though there are other means, but X-ray is none destructive).