Tag Archive for: bullets

Experts are often asked what kinds of entrance and exit wounds are produced by various types of ammunition. The answers to those questions are simple … it depends.

The rounds in the photograph below feature hollow point bullets similar to the rounds fired from the Thompson sub-machine gun I’m holding in the top and quite ancient photo. I pulled the picture from the buried crypt where I keep my old cop stuff.


.45 rounds and magazine

The .45 caliber rounds above are approximately the diameter of the Sharpie pens many authors use to sign books. That’s pretty close to the size of most entrance wounds inflicted when .45 caliber rounds pierce the flesh.

Pictured below is an entrance wound caused by 9mm round at point blank range, a close contact gunshot wound. Obviously, this was a fatal wound since I took this picture during the autopsy of the victim. Note the post-autopsy stitching of the “Y” incision (above right of the photo).

Also notice the charred flesh around the wound. This was caused by the heat of the round and burning powder as it contacted the victim’s skin. The bruising around the wound was, of course, caused by the impact.


9mm bullet wound to the chest—close range.

Next is one of the .45  rounds after it was fired from a Thompson machine gun.

Firing the Thompson at a sheriff’s office indoor range in Ohio. Notice the piece of ejected brass to the right of the major’s arm. I took the photo and was lucky enough to capture the shot of the brass casing during its fall to the floor.

The round passed through the paper target, through several feet of thick foam rubber, through the self-healing wall tiles of the firing range, and then struck the concrete and steel wall behind the foam. The deformed bullet finally came to rest on the floor. Keep in mind, though, that this all occurred in the blink of an eye, or quicker.

The above image shows a .45 round (above left between the 3″ and 4″ mark on the ruler) after a head-on strike with concrete and steel. The other distorting of bullets occurred when striking various surfaces from a variety of angles—ricochet rounds.

Bullet or Cartridge? Are You Writing it Wrong?

A bullet is the projectile portion of a cartridge, not the entire round.

4 components of a cartridge are the casing, primer, powder, and bullet

Casing: The container, such as brass, steel, or copper (pistol and rifle ammunition). Shotgun shell casings are typically made of plastic.

Primer: The primer is an explosive material that ignites the gunpowder when struck by a firing pin. Primers are located either in the center of of the base of the casing (centerfire), or in the rim of the base (rimfire).

Powder: The powder used in modern ammunition is smokeless powder, an explosive consisting either of nitrocellulose alone (single-base), or double-base, a combination of nitrocellulose and nitroglycerin).

Bullet: The cylindrical and pointed projectile that is expelled from the gun barrel.


A round is a single cartridge – “The magazine holds 15 rounds.”

Hitting the hard solid surface head-on caused the .45 bullet to expand and fracture which creates the often larger exit wounds we see in shooting victims.

Many times, those bullet slivers break off inside the body causing further internal damage.

The size of an exit wound also depends on what the bullet hits inside the body. If the bullet only hits soft tissue the wound will be less traumatic. If it hits bone, expect much more damage. Easy rule of thumb—the larger the caliber (bullet size), the bigger the hole.

Bullets that hit something other than their intended target, such as a brick wall or metal lamp post, can break apart sending pieces of flying copper and lead fragments (shrapnel) into crowds of innocent bystanders. Those flying ricochet fragments are just as lethal as as any intact, full-sized bullet.

For every action, there is an equal and opposite reaction.

Bullets don’t always stop people. I’ve seen shooting victims get up and run after they’ve been shot several times. And for goodness sake, people don’t fly twenty feet backward after they’ve been struck by a bullet. They just fall down and bleed. They may even moan a lot, or curse. That’s if they don’t get back up and start shooting again. Simply because a suspect has been shot once or twice does not mean his ability, or desire, to kill someone is over, and that, writers, is why police officers are taught to shoot until the threat is over.

The bank robber I shot and killed during a shootout fell after each of the five rounds hit him. But he also stood and began firing again after each of my bullets struck—one to the head and four to the center of his chest area. After the fifth round he stood and charged officers. Four of the five rounds caused fatal wounds. Yet, he still stood and ran toward officers. I and a sheriff’s captain tackled and cuffed him. In another instance, a man engaged in a gun battle with several officers. He was shot 33 times and still continued walking toward officers.

Always keep Sir Isaac Newton and his Third Law of Motion in mind when writing shooting scenes. The size of the force on the first object must equal the size of the force on the second object—force always comes in pairs.

Here’s Professor Dave to explain …


So, if your scene shows the shooting victim flying that twenty feet away from the person firing the rounds, the shooter would also fly twenty feet in the opposite direction. Ah, sounds silly, right? So toss this one in the trash can along with the use of cordite. No, no, and NO!

Equal and Opposite Reaction—Newton’s Cradle

Billy Buck’s heart pert-near stopped cold when he realized he was out of bullets. He frantically dug his grubby and stubby fingers down into each of the pockets of his crud-caked moldy jeans. Nothing. No bullets. He’d have to bare-knuckle and BS his way out of this one. He straightened his back and stood tall while squinting his eyes until they were practically shut, just as he’d seen Clint Eastwood do many times. Hey, it worked for him. Maybe …

Okay, what’s wrong with the above text (other than the poor writing)? I’ve seen this faux pas in several published works, and so have you, I’m sure..

Yes, bullets are only a portion of a complete round, not the entire item. If you already knew this then you’re ahead of the game.

So, while we wait to see if Billy Buck makes it out of this post alive, let’s examine a few other details about ammunition you may not know or have forgotten.

Bullets are Only Part of the Story

Acetic acide – reagent used in in the Griess test for detection of gunpowder residue. It’s also used for determination of nitrite in drinking water.

Action – The working mechanism of a firearm. For example:

  • Automatic – A firearm that feeds cartridges, fires, extracts, and then ejects spent cartridge cases. It will continue to do so as long as the trigger is fully depressed and there are cartridges in the feed system. These weapons are sometimes called “Full Auto” or “Machine Guns.
  • Lever – The breech mechanism of the firearm is cycled by the shooter who operates an external lever that’s typically located below the receiver. Operating the lever ejects a spent round on the way down and feeds a new round into the chamber on the way back up, if the gun is designed to do so. (Think old western TV shows where the cowboy fired his rifle by operating a lever action).
  • Revolver – A firearm with a cylinder having several chambers that rotate around an axis with each pull of the trigger .
  • Semiautomatic – A repeating firearm that requires a separate pull of the trigger for each shot fired. These are the typical pistols and rifles carried by police officers, recreational shooters, homeowners, concealed carry folks, etc. They are NOT fully automatic. Semi-autos operate by using the energy of each fired/discharged round to operate a sliding mechanism that  discharges and loads each round, until the weapon and magazine are empty.

Bore diameter – Diameter of a rifled gun barrel, measured from the tops of the lands. In a non-rifled barrel, such as a shotgun, the diameter is measured from inside wall to inside wall.

Breech loading – A breech-loading weapon is a firearm (a rifle, a gun etc.) in which the bullet or shell is inserted or loaded at the rear of the barrel, or breech; the opposite of muzzle loading.

Buckshot – Lead pellets ranging in size from .20” to .36” diameter. These are typically loaded in shotshells used by hunters, target shooters, and police.

Bullet – an elongated missile of some type (lead, etc.) that’s to be fired from a firearm.

Bullet, armor piercing – A bullet consisting of a hardened core other than lead or lead alloy.

Bullet, exploding – A bullet containing some sort of explosive that’s designed to explode upon impact.

Bullet, hollow point – A bullet with a cavity in the nose that’s designed to expand on impact.

Bullet, ogive – The curved forward part of a bullet.

Bullet, tracer – A bullet featuring a burning compound in its base. The hot and clearly visible flaming trail permits the shooter, and others, to view the bullet’s flight path.

Bullet penetration – The distance a bullet travels within a target material.

Bullet splash – The fragmentation and scattering/spattering of a bullet upon impacting a surface, such as metal or wood.

Bullet wipe – The discolored area around the immediate periphery of a bullet hole. It’s the smear/staining left surrounding the hole, caused by a combination of bullet lubricant, smoke components, lead, and even jacket material.

Cannelure – A groove or other mark surrounding the outside of a bullet that’s usually knurled, although, sometimes they’re plain. Cannelures are used to assist in crimping and identification of rounds.

Cartridge – A single piece of ammunition. One round.

  • Centerfire Cartridge– Any cartridge with its primer located central to the axis in the head of the case.

Rimfire Cartridge – A flange-headed cartridge with the priming mixture contained inside the cavity of the rim, such as .22 ammunition.

Chamber – The rear part of the barrel bore that accepts cartridges. Revolver cylinders have several chambers, for example (six shooters).

Chambering – Inserting a cartridge into the chamber. Officer Al Bundy, ready for a night of walking his downtown beat, loaded his 9mm and then chambered a round. He looked toward his partner and said, “Let’s rock.”.

Cordite – A double-base smokeless powder. It’s made of gun cotton, nitroglycerin, and mineral jelly. The mixture is molded and shaped into long cylindrical strands. Which are packed into individual casings. Cordite use and manufacturing ceased near the end of WWII. It’s not used in modern ammunition; therefore, modern day characters in novels and on TV cannot smell it when entering a crime scene. NO CORDITE in your stories!!!!

Cylinder – The rotating part of a revolver that contains the chambers (the individual slots where rounds are inserted).

Ejection – Expel a cartridge case, live or fired round, from a firearm.

Ejector/Extractor – The mechanism that expels cartridges or cartridge cases from a firearm.

Ejector/Extractor marks – Toolmarks on a cartridge case produced from contact with the ejector. Ejector/extractor marks are typically found near the rim of the cartridge and can sometimes be used to match a spent cartridge with the firearm that made the unique scratch, dent, etc.

Feeding – The insertion of cartridges into the chamber, either by hand or by magazine.

Feet per second – The unit of measurement used to express the speed of a projectile’s rate of travel.

Firing pin drag marks – Toolmarks produced during the extraction, ejection cycle, when a firing pin contacts a cartridge case. The same occurs when ejecting shotshells from a shotgun.

Firing pin impression – The indentation of the primer of a centerfire cartridge case, or on/at the rim of a rimfire cartridge case. The mark is made when the firing pin strikes the cartridge.

Billy Buck’s partner in crime, Onion Jenkins, tossed him a handful of cartridges (not bullets) just in the nick of time. So yes, he made it out of here in one solid, non-perforated piece.

Using fired bullets and casing examinations to solve murders is not a new thing. Not at all. In fact, I recall a case I worked back in the 80s where a man was murdered/executed by a drug dealer and a couple of his “employees.”

They’d kidnapped the fellow, a crack addict, because he’d ripped off the dealer by pinching cocaine from the supply he was supposed to sell, replacing it with pieces of soap which he peddled as the real thing. Customers quickly grew angry and, well, that’s when life grew short for the addict.

The trio of drug dealers took the addict to a secluded spot down a long and rarely used country road where they forced him to get on his knees. One of the men then fired a .32 round into addict’s head. They then pulled the body into the woods and left it for animals and weather to dispose of it.

One of the three couldn’t live with what they’d done so he contacted me. But he said right then and there that he’d never in a million years testify against the gang leader. I understood.

Without his testimony or further assistance, I knew I had find evidence that would connect the men to the crime. So I tailed the dealer day-in and day-out until he got careless and gave me a reason to search him. Long story short, the gun I found tucked in his waistband matched the one used to kill the kidnapped man.

Lab scientists at the Virginia Department of Forensic Science used a variety of methods to determine the match. Some of what they do when these things are presented to them for testing and comparison are:

Measure the base diameter of the evidence bullet and compare this measurement with known measurements published in reference material.

Determine the number and widths of the lands and grooves and compare to those in the current edition of the AFTE glossary.

Determine the widths of one land and groove impression. Then multiply by the number of total land and groove impressions. Use the mathematical formula C=πd to determine the circumference of the bullet.

Spiral grooves are cut into a gun barrel to produce rifling. Lands are the raised portions between the grooves.

Rifling – spiral grooves cut into a gun barrel in order to produce spin on the projectile. The spin/spiraling stabilizes it while in flight.

The categories of rifling characteristics are:

  • caliber (bore diameter),
  • number of land and grooves
  • direction of twist (the cut grooves produce the bullet’s spin which, in turn, improves accuracy and distance).
  • land and groove impression dimensions.


Physical characteristics of the evidence bullet—weight, shape, composition, nose design, and number and placement of cannelures, may help to determine the caliber of the fired round.


If a suspect firearm is submitted, a direct microscopic comparison is done between test-fired bullets and the submitted questioned bullet. ~ FBI

The FBI’s General Rifling Characteristics File (GRC) is often utilized when attempting to determine possible firearm types that could have fired an evidence bullet. This extensive file is particularly useful when the firearm used has not been located.

  • Comparison Microscope
  • Caliper/Micrometer/Ruler
  • Scale/Balance
  • Ammunition references
  • Stereo Microscope
  • Stereomicroscope (provides three dimensional viewing of a bullet).

When examining fired bullets, and when comparing them to known samples (bullets test-fired from suspect’s weapon and compared to round found at the scene or inside a body), investigators and/or scientists should record the following information

  • Caliber/gauge
  • Bullet/slug weight
  • The number of land and grooves
  • Direction of twist
  • Width of  lands
  • Width of grooves
  • Bullet diameter.
  • Composition of bullet.
  • Style.
  • Manufacturer/marketer of bullet/projectile. If applicable, use reference materials such as an ammunition database.
  • Detailed description  of the bullet.
  • Note type and position of cannelures.
  • Note any foreign/extraneous markings—shave marks, flared base, etc.
  • If possible, compare marks on bullets with tests from a firearm or with other bullets.

For nearly two decades, ATF has maintained a database of ballistic evidence (since 1999). The database—National Integrated Ballistic Information Network—contains well over 3 million bits of evidence and information that’s available to all law enforcement agencies.

Remember, writers, modern ammunition uses “smokeless” powder. It’s fairly stable, the quality is uniform, and it leaves little residue and a less offensive odor. IT IS NOT CORDITE!!!! Cordite manufacturing ceased at the end of WWII.

The characters in your stories CANNOT smell cordite, unless, of course, you’re writing historical fiction.