This is the science of ballistic forensics.
I actually take issue with ballistic forensics being considered a science.
How many actual "sciences" are completely created by, managed by, and confined to the law enforcement community?
Fact-- fingerprints have not been proven to be unique. They vary a great deal, but it has never been proven that fingerprints actually are unique.
Are fingerprints really infallible, unique ID? ? The Register
Bullet-to-gun matching seems pretty absurd to me as well. If you take two "identical" Glocks and fire 500rds of the same ammo through each, you'd be hard pressed to see which gun a 501st round came from. Oh, you can certainly pick one that seems more likely.
But HOW MUCH more likely? You already have a 50% of being right though pure chance.
This is the kind of "pseudoscience" that results from cops pretending to be scientists.
If I was a jury member, you better have a LOT better evidence than trying to convince me that a specific bullet (which is likely to be mangled beyond recognition) came from a specific gun (*THE* gun)rather than just *A* gun of that type.
JMO