can they match bullets to a specific gun?

Question

in the movies they say if you shoot someone,then they can take the bullet and indentify it to your registered gun,is that true?an if it is how is that possible?

Answer 1

Technically yes, but practically no. Ballistic fingerprinting is what you are referring to, it works on that each firearm makes unique markings on the casing and bullet that it fires; primer indentation, extraction marks, barrel rifling on the projectile, etc. States that require ballistic fingerprinting (some do others don't) fire a test shot and keep the casing on file for the registered firearm in question. So if a casing is found at a crime scene, they run the picture of it through a computer and look for a match with another in the system. In theory these markings are consistent through the life of the firearm, however the problem is that they are not. All it takes to defeat ballistic fingerprinting is filing the hammer, bolt or firing pin or scratching the barrel with a wire brush. And these things can also happen through the natural use of a firearm. Parts get worn down and barrel rifling changes or wears down after time. So it is possible to match a bullet/casing back to a specific firearm, as long as the gun is either new, and more importantly, is actually registered. In reality ballistic fingerprinting is absolutely useless and just an excuse to get federal firearm registration passed.

Answer 2

Many times they can match a bullet to a specific brand of gun by the rifling marks. Sometimes they can match a bullet to a specific gun, but only if they have the gun. A lot of times the bullet won't tell anything....

What you see in most movies is 99% B.S. The very last episode of CSI I ever watched, a fired bullet sitting on a stump was 'picked up' by hurricane winds and killed some lady. I refuse to watch such bad science.

Answer 3

Can they match a single suspected gun to a bullet and a casing found at a crime scene? Yes. Can a lab take a single round fired from one of 100 identical firearms made during the same production run and detect which one fired it? No way. Unless the gun that fired it has some serious barrel problems.

Answer 4

I think they often can do it. They can compare the bullet with a particular gun and determine if it was or wasn't the weapon it was fired from.

I think this only applies to traditionally rifled barrels. Apparantly, pistols with polygonal rifling, which is made up of more smooth hills and valleys as opposed to the slits of conventional rifling, it isn't possible to make conclusive analysis. Glocks are an example of a company that uses polygonal rifling.

It isn't sure though that they can do it by any standard. Often times the bullet fragments or with hollow points they expand a lot and any marks will be too distorted. FMJ pistol bullets are most likely to yield a clear sample for comparison.

Answer 5

It's called 'comparing tool marks`.
They can get the rifling direction, twist rate,
and sometimes match the barrel wear marks
from one particular gun to the bullet in question.
The same goes for cartridge cases where there
are distinctive marks from the chamber, extractor,
firing pin, and ejector.
It depends on microscopic examinations of the
bullets and cases, and is not an exact science, but
under good conditions, pretty strong opinions can
be formed.

Answer 6

One of the really cool things about the ability to identify what weapon fired what bullet is that it gives historians the ability to recreate history in ways that we could have never imagined. I am no fan of war don't get me wrong but I love history. I visit Montana regularly on business and have visited the site of Custer's last stand several times. The ballistic recognition ability has made it possible to make positive identifications of what gun killed what person and so you get very detailed accounts of the battle, knowing where each soldier and indian fell. For years history presumed from written accounts that Custer was mentally ill and basically a mad man with a death wish. Once you see and hear the reenacted battle it becomes quite evident that he was a raving lunatic. I actually got to photograph for the historical society as they ran strings from the shooters to the victims and gathered so much information all because of the ballistics testing. It's pretty awesome stuff.

Answer 7

Yes. Not only can they identify the caliber and make of the gun that fired it, they can also find the model of the gun. The only three ways to prevent them for making a dead-on match is to prevent the rifling from being identified or preventing them from firing an additional round fro your gun to see if it matches.
1. Intentionally causing damage to your gun barrel will prevent the FBI (police) from making a dead match. (but that itself is highly suspicious)
2. If you didn't use your gun to do the shooting, then they can't pin you that easily.
3. Or do something to the bullet as it exits the gun to destroy its rifling marks.

Answer 8

Yes they can.

Rifling is the process of making grooves in gun barrels that imparts a spin to the projectile for increased accuracy and range. Bullets fired from rifled weapons acquire a distinct signature of grooves, scratches, and indentations which are somewhat unique to the weapon used. In simple terms, when a slug travels down the barrel of a gun it gets cut up ever so slightly. If the slug is found intact (or partially intact), those cuts can be matched against the barrel of the gun with great accuracy. Additionally, shell casings can often be matched up to firing pins using a similar methodology.

Answer 9

not just from the registration they can narrow down which gun it came from by the caliber and number of groves on the bullet some company's use 3,4, or 5 grove rifling but they still need to have the gun to make a match

Answer 10

they can. the rifling in the gun leaves a unique pattern on the bullets copper jacket. no two are alike. however, by using frangible rounds(rounds that completely shatter on impact) you can make rifling identification immposible. but they can still trace the bullet using metallurgical tests that will show which barrel the bullet was fired from.