Bullet Construction Part 2- FirearmsID.com

The shape of a bullet dictates the aerodynamic and impact characteristics of the bullet. Manufacturers always seem to be tinkering with the shape of bullets. They are trying to find the right combination of materials and shape to make the perfect bullet.

So what is the perfect bullet? Well good question. The answer is that it hasn't been made yet!

Most bullet manufacturers will produce a variety of bullet shapes within one caliber. Let's briefly discuss a few of them.

All bullets will generally fall into several distinct shapes. These shapes usually involve variances in nose and base of the bullet.

The two most common bullets for the longest time have been the round nosed lead bullet and the full-metal-jacketed bullet. Common examples of these can be seen below.

These bullets have a solid nose and as a result they remain fairly intact when they strike soft targets. In a lot of cases they will pass right through a target when they don't encounter something significant like bone.

Solid nose bullets are commonly used in target practice and shooting competitions because they are relatively inexpensive and have decent ballistic characteristics. But that's where the use of the solid nosed, non-expanding bullet ends.

Because these bullets have a tendency to pass easily through a target the energy they have left is wasted energy. Let's not misunderstand the purpose of a bullet when used against a living target. The sole purpose of the bullet is to kill or incapacitate that living target. So, wasted energy is not a desirable characteristic of bullets used by law enforcement or by private citizens for hunting/self-defense.

The big focus today in bullet design is creating a bullet that has an expanding point. This expansion is needed to slow down the bullet when it strikes a target. A bullet that expends all of its energy in a target is more efficient and in turn produces more damage. Think of the nose of a bullet as being a parachute. When it strikes a target it is designed to open up expanding its surface area as much as twice the original diameter of the bullet. This expansion is typically called "mushrooming" as the bullet takes on a shape similar to a mushroom. See the example below.

Bullets designed to expand usually have a hollow cavity formed into the nose of the bullet. These are referred to as hollow-point bullets. Below are some common hollow-point bullets.


Federal Hyda-Shok bullet with center post.	Remington semi-jacketed hollow-point bullet

But wait just a minute! Bullets can expand too much if they aren't put together just right or can fail to expand sufficiently. A bullet that expands too much can break up into smaller pieces and this fragmentation can limit penetration. This is not necessarily a bad thing and a bullet designed to fragment is called the Glaser Safety Slug seen on the previous page. This bullet is designed to break apart scattering numerous small lead pellets throughout the target. Each of the small pellets will create it's own wound track and cause an enormous amount of bleeding. Unfortunately this type of bullet must hit the torso of a body to be effective.

Sometimes more penetration is desirable. Take for example shooting at an elephant. If the bullet is designed to expand rapidly it will not penetrate deeply enough to get the job done. Bullets that have controlled expansion may have a soft area of lead exposed at the nose and usually lack the hollow-point cavity. Some examples are below.


Semi-jacketed Soft Point bullet	Jacketed Soft Point bullet

Police officers also need a bullet that has decent penetration characteristics. They need a bullet that can possibly pass through the windshield of a car or through heavy clothing and still retain the integrity to strike the target with enough energy to disable the threat. This is accomplished a lot of times by increasing the velocity, weight, and hardness of the bullet. A good example of a bullet designed for Law Enforcement use is the Speer Gold-Dot bullet seen below. This expanding point bullet uses a copper jacket that is bonded to the lead core to slow down the expansion of the bullet. When it mushrooms you will see a unique small copper dot at the center of the hollow-point cavity.

The base shape of a bullet can also be an area firearm examiners will use to help determine the manufacturer of a bullet. Some bullets have bases that taper in, these are referred to as "Boat-tail" bullets. Others may have expanded bases or banded bases.


Gas-check copper base lead bullet	Remington Golden Sabre expanded base bullet	7.62x39mm boat-tail bullet

Well, as you can see there are seemingly endless of variables when it comes to the characteristics of bullets. I've only touched primarily on centerfire handgun ammunition in this summary but rimfire ammunition, and rifle ammunition offer just as many options and challenges for firearm examiners. Information regarding shotshell construction can be found here.

It will always be impossible for firearm examiners to remember all bullet types. Some are not widely distributed and new bullet designs come out it seems everyday! But we still try. It may not seem like a big deal but in a trial the bullet manufacturer or caliber may end up being a very critical piece of evidence that will help with a conviction or prove the innocence of a defendant.

Now that you've been introduced to various bullet types and configurations try your luck at the Projectile ID Quiz located in the Resource Section! You should review both this Bullet Basics section and the Shotshell section prior to taking the test.

To help examiners narrow down the possible caliber or manufacturer of an unknown bullet we have created a searchable database of over 1100 known bullet types. Click the link below to go searching!

Bullet Basics 2- Shapes