What is the difference between a .45 TZZ bullet and .45 WCC bullet

[amateur2010]

I am doing research and know next to nothing about guns. If one .45 semi-sutomatic gun fired two bullets- one manufactured by TZZ and one by WCC would there be any difference in how the guns are fired? Are the bullets exactly the same except for the manufacturer? My understanding is that WCC is Western Cartridge Company and made by the US military and TZZ is made by the Israeli Military Industries. I understand that the TZZ may have a crimped primer but I am not even sure what that means. Any insight would be much appreciated!

[mapsjanhere]

Assuming both are military Full Metal Jacket (FMJ) bullets (from the crimped primer, that's something you normally only see on military rounds) of the same weight, no difference whatsoever. Now, many manufacturers make a multitude of bullets for the same caliber, different weights, different construction, but that is not something you can tell just by the manufacturer's name.

[amateur2010]

Thank you! What if one is a FMJ and one is not? What is the difference?

[mapsjanhere]

FMJ typically makes a caliber size hole, you might get lucky and it passes through you without hitting anything vital, you might not.
Semi-jacket rounds with or without hollow points or fragmentation lines expand significantly in the target, depositing a lot more energy in the body. You might have an entry wound, no exit wound, but everything inside is hash.

[amateur2010]

Thank you!

[James K]

Bullet jacket composition does vary, not only by manufacturer, but with different lots of jacket metal used by the same manufacturer. Places like the FBI labs try to keep up with those variations but usually can't. At one time, the FBI analysts reported in many cases that bullet x (the crime bullet) came from box y (found in the possession of a suspect).

The problem was that they were finding what they wanted to find and finally admitted that they just couldn't make that determination except in a very few cases. That caused a big hoorah and some convictions obtained mainly on bullet jacket evidence were overturned on appeal and retrials ordered.

Markings on the bullet caused by the rifling in a barrel are on much more solid ground. Like fingerprints, they are unique, even from barrels made at the same time by the same factory. Even that is not 100%, though, since the bullet can be damaged by impact or damage to the gun (accidental or deliberate) between firing the crime bullet and the time a comparison can be made can prevent an accurate comparison.

Jim

[Rampant_Colt]

Loaded ammunition are called cartridges. A "bullet" is what's shot from the barrel. The two terms aren't interchangeable.

There's no difference between WCC or TZZ .45 ACP ball ammo.
Both fire a 230gr full-metal jacket bullet at roughly 800-880 FPS. Crimped primers will not affect anything

[amateur2010]

As far as the marks on the shell casings of the .45 WCC and TZZ, would the breechface impressions on the casings be any different if one was a FMJ? My understanding is that the impressions vary on the pressure exerted on the bullet itself as it leaves the chamber-is there anything about a FMJ that would make the breechface impression different?

And do any of you know an expert who would be willing to email me privately about these questions?

I am an attorney preparing for trial.

[Rampant_Colt]

Originally Posted by amateur2010

As far as the marks on the shell casings of the .45 WCC and TZZ, would the breechface impressions on the casings be any different if one was a FMJ? My understanding is that the impressions vary on the pressure exerted on the bullet itself as it leaves the chamber-is there anything about a FMJ that would make the breechface impression different?

And do any of you know an expert who would be willing to email me privately about these questions?

I am an attorney preparing for trial.

There's no way to tell the type of bullet used based on breechface impressions. Generally premium ammunition will have a laquer-sealed primer and nickel-plated casings.

Are you trying to determine if the casings in question were "hot" handloads?

Every handgun has its own unique breech imprint▬Glocks have a rather distinctive breechface marking

[mapsjanhere]

I think it would help if you'd tell us what you're trying to solve. One gun firing mixed cartridges, two guns each firing one brand etc. Each scenario might leave different things to look for.

[amateur2010]

I am trying to figure out if shell casings of different brands could have different breechface impressions. If an expert says that the breechface and firing pin impressions on the shell casings are a match, how can he tell that for sure if the gun wasn't recovered when the shell casings are different brands and some are FMJ and some are not?

Thank you! And again, I am willing to retain an expert in this matter as well. I am looking for someone with experience in firearm examining as well as gunshot residue who has worked with both prosecution and defense.

[VUPDblue]

I am trying to figure out if shell casings of different brands could have different breechface impressions. If an expert says that the breechface and firing pin impressions on the shell casings are a match, how can he tell that for sure if the gun wasn't recovered, when the shell casings are different brands and some are FMJ and some are not?

Because the breech face and firing pin impressions are tool marks, nothing more. The breech face and firing pin only come into contact with rear of the cartridge, the bullet loaded into the cartridge makes no difference in relation to what tool marks are left on the cartridge by the breech face and firing pin. The tool marks would still be the same regardless of manufacturer of the cartridges as well. I guess you could liken the relationship between the breech face and the cartridge to the relationship of a rubber stamp and paper. You can take a rubber stamp and press it to paper, cardboard, drywall etc... but the mark left behind will be the same. The impressions left by a breech face or firing pin are like fingerprints. With tool marks, each impression is unique to the tool that left it. HTH.

[mapsjanhere]

So, you have one gun that fired multiple shots (leaving cases behind) from multiple brands. Usually I'd expect the expert to compare bullets since the rifling impressions are more individual than firing pin etc. Typically I wouldn't think the breech face and firing pin impressions are "a sure match" unless there's other evidence, or the gun has some unique characteristic (like a damaged pin or breech face leaving a unique imprint).
But they are probably pretty specific to a weapon type, so if the witnesses say one guy was shooting a Glock and the other a 1911, assigning the cases to each gun is most likely reasonable.

[Rampant_Colt]

Every handgun has unique breechface tool marks that should easily match up the gun in question with the spent shell casings by using a stereoscopic forensic comparison microscope. It basically does a visual side-by-side comparison of two different objects, and scientifically proves if they're a match or not.

[Jim Watson]

I have always considered TZZ to be a pretty faithful copy of WCC ammunition.
BUT it is made a world away and is not going to be identical. If the brass were a little different in temper and the primer a different cup and compound, the tool marks on chamber, breechface, extractor, and firing pin could show up differently. This is one reason M Ayoob recommends factory ammunition for self defense, you will likely have the rest of the box at home to serve as exemplars if forensics ballistics examination is called for.

[SDC]

You can have slightly more or less pronounced markings depending on things like brass or primer cup hardness, but not really enough to make a difference in determining that a given casing was fired in a particular pistol, because the metal of the pistol is so much harder than the alloy of copper used in ammunition components.

[Jim Watson]

There was a lot of difference between Federal and Winchester fired primers from my Springfield UC. Maybe they could be matched by a skilled operator under a microscope but they had major macroscopic differences.

[Johnny Guest]

Take another look at the firearms examiner's report. If the conclusion is made solely on the basis of comparison of two (or more) fired cartridge cases, the examiner likely looked at three items: The breechface markings on the base and primer, the firing pin impressions on the primers, and the extractor marks on the "rims" of the cases. It may be difficult to reach a conclusion based on only one of these factors, but easier using two or three.
Johnny

[Johnny Guest]

Originally Posted by amateur2010

. . . I am willing to retain an expert in this matter as well. I am looking for someone with experience in firearm examining as well as gunshot residue who has worked with both prosecution and defense.

The Association of Firearm and Tool Mark Examiners is a professional organization that is well thought-of in the criminal justice community. They provide an "Expert Referral" directory on their web site. See HERE and check the list on the left sidebar.

Probably a majority of AFTE members are employed by city, county, and state crime labs. Many, however, do independent consultations. Like most expert witnesses in whatever field, their time is dear, but a few hundred dollars spent early on may be very worthwhile.

Being a long time peace officer, now retired, I don't know whether to wish you good luck, counselor. I do hope that true justice will be done.

Johnny