I dont get why its important for Law Enforcement to track guns anyway. I mean besides the obvious potential for illegal sales. Or is that the only reason?
Just because a Glock is used in a crime doesnt mean it can be traced. The only identifying feature are from the barrel which can be swapped in 15 seconds.
Nope. There is more to firearms identifications then just the barrel. Might want to read up on it.
https://www.atf.gov/firearms/automated-firearms-ballistics-technology
"As with fingerprints, every firearm has unique characteristics. The barrel of a weapon leaves distinct markings on a projectile. The breech mechanism also leaves distinct markings on the cartridge case. These markings are produced by the breech face itself, the firing pin, extractor, and ejector."