Sorting it all out is complicated because ... We’ll get to the 223 Wylde shortly. The cartridge cases of the 223 Rem and 5.56 NATO appear identical on the outside, but 556 cases can have ...

FOX31 got into the lab to see how it all works. “I place the cartridge case in this holder,” Jefferson County Regional Lab Forensic Scientist Erin Mulligan explained during a demonstration.