So standard bullets get the serial number on them from the gun that was used when the hammer strikes, is that correct? then the bullet that enters the target has a groove pattern that can be compared to other bullet patterns right?

What about with shot gun cartridges? I imagine (if it is correct) the cartridge gets the serial number imprinted on it. But how do they individualize the pellet pattern to other shot gun blasts? arent they just a spray of lesser projectiles?

if someone takes the cartridge shell from a scene of a crime, they just have a hunk of mess to compare to any possible hunk of mess a shotgun can create?

I am always concerned about questions like this. Are you asking us to help you commit the perfect crime?

As to your question, they don't, other than metallurgical and chemical anolysis of the shot and GPR, but that is just anecdotal evidence.

I just mean it as seen on tv shows... bullets have striation patterns to be matched against archived ballistics data. How do they do it with shot gun pellets.

Unless the gun is already in the system then they won't know which gun fired it.

The point being they have comparison capabilities... to match to an exact gun. With shot gun blasts, is it pretty much

-cue scene from the matrix- shot guns... lots of them...

No. The bullet is marked by potentially unique variations in the gun barrel's rifling; nothing is guaranteed though, these variations aren't intentional. The firing pin, hammer or whatever doesn't actually come into contact with the projectile, just the casing which is ejected by the gun. The markings on that generally indicate the type of ammunition, the manufacturer and sometimes the year of manufacture, but seldom anything more than that.

This is called ballistic fingerprinting. You will get the firing pin print (not a serial number obv), not the striations. On CCNA's point, you know what you need to be doing to stay safe, don't freak us out too much. You don't want to get got.

Never mind I had zero understanding about bullets being fired this whole time: What I Thought:

1. casing gets imprinted with serial from hammer.

2. bullet has striation that matches gun

3. considering i never registered the casing ejects from the chamber, and thought it mushed into the target with the bullet..

/facepalm not surprised nothing I thought I was considering matches up to the reality of the situation

so do people collect the casings more for the identity scenario or for finger print scenario?

Law enforcement will collect everything they can, and use it in any way they can.

i meant the criminals in movies is it no loose ends for them or a specific reason

1. Nope. But there is a "fingerprint" left by a weapon when the hammer strikes the primer. Hammer and pins wear (drift, chip, blunt).

2. Projectiles will also leave a "fingerprint" based on design of round (ball, wadcutter, hollow point, weight, manufacturer, cartridge charge, composition) and weapon manufacturer (barrel rifling or twist rate, dimensions, etc.)
3. Wut?

People most likely collect these for the following reasons;

• Recycling
• Range protocol
• Reloading
• Reducing criminal footprint

Lets call this case! SOLVED!

I mean if you really wanted to just use antique firearms they do not have to be registered

Shotgun barrels have no rifling (spiral lines to make the projectile spin).... Good luck tracing lead pellets that are significantly smaller in diameter than the barrel and almost zero deformation that took place before hitting the target...

typically true but there are rifled shotgun barrels available for when "slugs" are used

shhhhhh.... Basics... ... I don't like slug barrels myself. I always felt that if the job requires a rifled barrel, use a rifle. I admit that when you try to shoot slugs from a regular shotgun barrel, results are pretty poor lol.

Not being rude, but I am going to guess that you don't own a firearm, haven't fired one, and haven't looked at a spent case.

registered? I'll pass