Reply #26: Alin, there is usually a set of micro characters on a part of the gun,

[jmg257]

typically the tip of the firing pin, or maybe in the chamber of the pistol (usually part of the barrel in a semi auto). When the pin strikes the primer, or the brass expands into the chamber, a set of characters is imprinted on the fired casing/brass. Each gun's character code would be unique.

The problems are it would be QUITE easy for a criminal to swap out the firing pin, swap out or sand down the chamber/barrel, or even to get fired brass from some other gun (from any of the 1000s of ranges around the country) to leave at a scene, or to just use one of the 300 million+ guns out there that don't have such technology.

I think one of the biggest nightmares is fired brass. EVERY round ever fired should be accounted for - picked up and discarded - by police, civilians, any one else subject to using arms of this type. Millions of rounds are now potential "evidence" that could seeded at a crime scene.

Also of course, is the added expense of incorporating the process into manufacturing, and keeping a data base - a registration scheme - of every gun sold and exactly to who. Because registration leads to confiscation - it is an infringement.