
Author
Charles Cooper
USMC, Amphibious Assault-1990-1994 1 deployment to Somalia.
2nd Ranger BN, 75th Ranger Regiment
SOCM Medic-2005-2015,
8 deployments to Iraq, Afghanistan and Horn of Africa
BASIC AMMUNITION TYPES
The right tool for the job. When it comes to choosing your bullets, you want the right size and type for the weapon you plan to fire. But how do you know which bullet you need for your specific firearm?
All ammunition is designated by measurement, which can be found in two separate standards. There is the U.S. standard and the metric system of measurement that is used in just about the rest of the world. When you are reading a measurement in the latter, you will usually find it in a diameter to length ratio. For instance, a 9x19mm cartridge is 9mm wide and 19mm in length.
Shotgun shells have a different type of measurement called a “gauge”. These also come in a variety of sizes, with the lower numbers offering the larger diameters. The most commonly known size of shotgun shell is the 12 gauge which measures out to be 70mm in length or roughly 2 ½ inches.
CARTRIDGES
A bullet is just one part of your ammunition. There are four parts that make up the total sum of a cartridge. Each item of ammunition you load into your firearm is actually the cartridge not only the bullet.
The four components of a cartridge are the following:
1. Case – This component houses all of the active components needed to fire a bullet. Cases are usually manufactured from brass, nickel, or steel.
2. Primer – This component is used to ignite the gunpowder within the case. If you look at the end of the cartridge opposite the bullet, you will find a small round dimple, this is where the pin of the firearm comes in contact with the case to ignite the propellant.
3. Gunpowder – This component is also known as propellant. Without the powder, your bullet will not fire.
4. Bullet - This component is your projectile. When you fire a weapon to hit a target, this is the only part of the ammunition that is physically expelled from the firearm. The case either remains in the firearm or is ejected, based on the type of weapon you are firing.

SHOTGUN AMMO TYPES

BIRD SHOT
This ammunition is used for hunting waterfowl. It's best for pheasant and duck and comes in a range of sizes. When selecting the bird shot that is right for your needs, the higher the number you choose, the smaller the pellets inside the shell. Larger sizes mean fewer pellets per load.

BUCK SHOT
If bird shot is ideal for hunting fowl, then you can guess what buck shot is best for hunting. You guessed it – deer and medium to large sized game. This type of shotgun ammunition relies on mostly larger pellets in each shell which means there are fewer pellets per load. Buck shot is also a popular type of shotgun ammunition for use as a home and personal protection load.

SLUGS
A slug is basically a bullet used in a shotgun. These expel one solitary lead projectile when fired which means you need to rely on your own accuracy to hit your target in much the same way as a pistol. Slugs are mainly used for hunting bear, boar, and whitetail deer.

BREACHING ROUNDS
Breaching rounds are frangible shotguns rounds that are created to disintegrate on impact. They start off as lead powder that is pressed into a lead projectile under low pressure so it disintegrates easily. They are great for shooting the locking mechanisms out of doors and hinges off doors to gain a method of entry to a target. They are made to disintegrate so they do not over penetrate into a room and injure hostages when the breacher in firing rounds in the locking mechanism and hinges.

DIFFERENCES IN SHOTGUN AMMO TYPES
The biggest difference among these types of ammunition is in the spread of the shot patterns. Firing bird or buck shot allows for a multitude of different size pellets to hit your target versus a slug which is one single piece of lead. Remember, smaller pellets allow for more of them to be ejected at your target. But larger pellets typically have a harder impact with fewer of them fired at the target.
RIFLE & HANDGUN AMMO TYPES

RIMFIRE
When you fire any weapon, the firing pin comes into contact with the primer to ignite the propellant and eject the projectile. The primer of rimfire ammunition is located in the rim of the cartridge.

CENTERFIRE
With centerfire ammunition, the primer is located in the center of the cartridge, so the pin comes into contact with that small round dimple in the middle.

DIFFERENCES
Besides the obvious difference in placement of the primer, rimfire cartridges are typically used in ammunition with lesser pressure loads. Therefore, they are ideal for hunting small game and shooting at targets because of their lower velocity. Centerfire cartridges are often used with higher velocity rounds and chosen for self-defense.
AMMUNITION CALIBERS

.22LR
The .22LR (short for Long Rifle) is easily the most popular caliber out there because it's inexpensive and well-suited for hunting, target practice, and self-defense situations. This rimfire round doesn't pack a big punch so there isn't a lot of recoil when fired, making it a great choice of ammunition for training purposes and shooting varmint like squirrels and rats.

.223/5.56X45
The .223 Remington is intended for use in a variety of semi-automatic and manual rifles. This is a high-velocity caliber that excels in destroying targets at short-distances. Typically used for small game hunting, the .223 Remington is also ideal for medium game. The 5.56x45 cartridge evolved from the .223 Remington and has been used primarily in M-16's. This is standard issue for NATO forces as well as military and law enforcement personnel in non-NATO countries. Civilian model AR-15’s shoot both of these ammo's. The short and long range damage potential of the cartridge gives it serious stopping power.

.380 ACP
Ideal for short range firing, the .380 ACP (short for Automatic Colt Pistol) is popular for its use in compact and lightweight firearms. Highly effective at close range, the .380 is a low recoil caliber without a whole lot of stopping power. But it can still be used as a reliable self-defense round. .380 is great for sub-compact pistols that are highly concealable.

.9MM
Identical in diameter to the .38 Special and the .380, the .9mm round is extremely popular with firearms enthusiasts and casual consumers alike because it is equally effective for target practice and self-defense. The recoil is not extreme and it's an easy round to fire with accuracy. These are some of the many reasons it has been a preferred caliber by multiple law enforcement agencies at the federal and state levels across the United States, including the FBI.

.40 S&W
Similar in many ways to the .9mm with the exception of a higher recoil, and more knock down power the .40 S&W is available in different projectile weights from 155 grain to as much as 180 grain. This was the caliber of choice for the FBI after it went to the 10mm auto because of the 9mm underperforming in the 1986 Miami shootout. The 10mm was too powerful a weapon for female agents so they created a 10mm light load that would eventually become the .40 S&W. The agency has since returned to using the 9mm.

.45
This was long considered the preferred caliber of bullet for law enforcement and military for decades. The projectile size is well into the 200+ grain range and the recoil is on the moderate side. This is a bullet that offers serious stopping power.

.357 MAGNUM
This caliber is less popular than it once was, but that doesn't mean it's no less an effective caliber of bullet. The recoil is significant and offers serious stopping power in a much heavier projectile weight than some of the more common calibers on our list. It's a bullet that is found mostly in revolvers.

.50BMG
This massive cartridge is the .50 Browning Machine Gun cartridge. It entered service in 1921 as belt fed machine gun ammo for the Browning M2HB .50 cal machine gun. It it still used by militaries around the world today. It is also used by military snipers, during Vietnam sniper would delink machine gun ammo and fire it one round at a time through scoped machine guns. Later bolt action .50 cal rifles were created and chambered in .50 BMG, soon after match grade ammunition was created and is still being eveolving so sniper can accurately make over 2000 yard shot with these massive rifles. Now there are long range shooting competitions with .50 BMG match grade competition rifles.
TYPES OF BULLET
CARTRIDGES
Full metal jacket – Among the most common types of bullet, the full metal jacket describes a lead projectile that has been “jacketed” in a surrounding metal that is harder and stronger. This is typically copper but other metals can be used to create a full metal jacket projectile. One of the biggest advantages to a full metal jacket round is the lack of lead that is left behind in the barrel when fired. These are also called TMJ for total metal jacket ammo, Total metal jacket is basically the same thing just renamed by other manufacturers.
Hollow point - The very opposite type of bullet to the full metal jacket, a hollow point is designed to expand in size when it penetrates a target. Used by many law enforcement personnel, hollow point rounds are preferred because they are built to stay lodged inside of human tissue after impact. The projectile is able to do this because it lacks the hard metal exterior found in a full metal jacket type of bullet.
Soft point - Combining the best of both the full metal and hollow point types, the soft point bullet is a jacketed projectile that has been manufactured to expand wider than the diameter of the entry point when fired into soft tissue.
Frangible bullet - Frangible ammunition is usually made of sold copper. It starts out as a fine copper powder it is then pressed in a mold under extreme pressures above 50,000 PSI and turns into a solid copper projectile. This ammunition is great for shooting steel targets or used by Special Operators when operating in environments where the wall are steel, like a ship or oil platforms. When the ammo strikes a hard surface it still impacts with extreme energy but instead of fragmenting in small pieces that ricochet and can cause damage, frangible ammo disintegrates back into powder. This ammo can be great for training on steel targets of real world situations.
