Thanks for the information. I thought the connection was from recovered cases. Glocks are notorious for being unable to match bullets to individual guns.
No problem. After many years OSBI became very desperate to find the perp. It was a particularly heinous crime.
Forbes Crime covers it in multi-part story from start to finish. It’s like a mini-novel and a great read.
Murder: Connecting the Dots More than Once in Oklahoma - Part 1
It’s because of the rifling. Most rifling in weapons are cut into the barrels by specialized milling tools. The rifling in Glocks are pressed into the metal by something called drop hammer forging. the barrel blanks are slid onto a forming mandrel and then the rifling is hammered into the blank. this leaves less microscopic toolmarks that gives milled rifling its “signature”. However ejectors and extractor claws probably would give the bullet casing enough of a signature to identify a particular weapon.
CC