knowing what gun fired the shot

[Springfield45]

All this ballistic fingerprinting crap only works if your have all the variables. Like a bullet, a spent shell casing, a gun, and a suspect. If you are missing one of these a defence attorney can shot holes in a prosecution. Missing two or more and DA will not even file for an arrest.

If they find a shell casing at a crime scene it is easy to tell the caliber. Based on scratches from the magazine, feed ramp, chamber, and the primer marks you may be able to tell a type of weapons used. A shell casing is worthless with out the gun to match it to and a suspect connected to the gun.

A bullet can tell you limited information about the weapon. For instance a .308 caliber bullet can come from hundreds of different manufactured rifles. But a bullet that is .327 caliber would be easier to speculate. A bullet with out a gun to match it to and a suspect.

Even it you have a 40 caliber shell casing and a 40 cal. bullet, all you will really now for shore is that the weapon used is a .40 caliber semi auto handgun. Maybe you can tell it was fired from a S&W Sigma because of the primer marks. Maybe you can tell it was a HK USP because of the rifling marks on the bullet. This will lead you no where with out a gun to match it to and a suspect. There are many variables that can be involved.

What if the weapon used was a TC contender with a 9mm barrel? What if a sabot round (a smaller size bullet in a plastic wad like a .25 cal. bullet fired from a .38 cal.) was used? How much information can be speculated from a Glaser Safety Slug if all you have is the fragmented bullet?

[Sailormilan2]

All this is rather interesting in considering what happened in Oklahoma earlier this year. There was a shooting involving some type of "40 caliber" handgun. The OBI(Okalahoma Bureau of Investigation) released a news report that they wanted all people in the area to voluntarily bring forth their 40 cal weapons for testing to see which one might have been involved. Failure to do so would result in that/those person/s be investigated as possible suspects.
No mention was made of what possible Brand of Weapon it might have been. Which one might have thought would be possible, if there were shell casing availible. If it was just bullets/slugs availible then they should have included the 10mm also.
So, it appears that someone had/s no clue as to what they are doing. Scary thought.

[M. Sage]

Change the barrel, ejector, and give the firing pin hole area a good scrub with wool, and wha-la, you have a "new" gun.

Those programs where they sent a fired bullet and shell have proved useless in identifying a gun. Only a small percentage of crimes are solved using the database. In fact, in some states they want to get rid of it because it has proved useless and enormously expensive.

All you have to do is put a couple thousand rounds through the gun. Ever notice how some pistols and auto-loading rifles feed better after a "break-in" period?

[Fire in the Hole]

All this is rather interesting in considering what happened in Oklahoma earlier this year. There was a shooting involving some type of "40 caliber" handgun. The OBI(Okalahoma Bureau of Investigation) released a news report that they wanted all people in the area to voluntarily bring forth their 40 cal weapons for testing to see which one might have been involved. Failure to do so would result in that/those person/s be investigated as possible suspects.
No mention was made of what possible Brand of Weapon it might have been. Which one might have thought would be possible, if there were shell casing availible. If it was just bullets/slugs availible then they should have included the 10mm also.
So, it appears that someone had/s no clue as to what they are doing. Scary thought.

I wonder how many Oklahoman's actuall fell fort this rouse. Akin to: We've had a hit and run involving a fatality. We have no idea what kind of vehicle was involved. A citizens are requested to bring their vehicles in for police inspection to check for damage/evidence. Failure to submit will result in all vehicles in OK being suspect.