Beginner's Guide to Types of Ammo

One of the most critical aspects of shooting is selecting the right ammunition. With so many ammo options available, knowing which one to choose and use can be difficult.

Before discussing the specifics of ammo selection, it's important to understand the basics. Ammunition is not a one-size-fits-all category. It comes in various calibers, designs, and uses. Each shooter will have preferences that affect how different types of ammo perform.

Compatibility is the primary factor in narrowing down the selection options for your gun. If you have a 9mm handgun, you won't consider rifle ammo to fill it. However, 9mm ammo has several options and styles, so you'll want to research whether you prefer "jello shots," full metal jackets, or hollow points.

Use this guide to get to know the details of the ammunition available and decide which is best for your needs.

Ammunition Basics

Ammunition consists of four main components:

Ammo Anatomy

Shotgun shells have a fifth element, the wad, which separates the powder from the shot or slug.

Types of Ammo

Ammunition can be broadly categorized based on the type of firearm it's used with.

Rifle & Handgun Ammunition

The two types of rifle and handgun ammunition:

• Rimfire - has the primer located around the rim of the cartridge base
• Centerfire - has the primer in the center of the cartridge base

Shotgun Ammunition

Shotgun ammunition is produced in three main types:

• Birdshot - contains many small pellets and is used for hunting birds and small game
• Buckshot - contains fewer, larger pellets and is used for hunting large game and for self-defense
• Slugs - contain a single solid projectile used for hunting large game for self-defense

Specialized Ammo

Specialty ammunition types offer unique characteristics and advantages tailored to specific shooting needs.

• Subsonic - is designed to operate at velocities below the speed of sound. It does not yield the "crack" of supersonic ammunition. Subsonic bullets are often heavier, so they retain energy at lower velocities. They also produce less noise than standard rounds. The military and law enforcement often use them when lower-noise rounds are needed. They are also used by hunters who need lower-noise rounds to avoid disturbing wildlife.
• +P (plus pressure) - are rounds loaded with higher pressure than standard rounds, resulting in higher velocity and energy. They are only recommended for use with handguns that are designed to handle ammunition with greater pressure and recoil. Law enforcement typically uses high-pressure ammunition to provide reliable and powerful duty ammunition and for personal defense.
• Match-grade - is designed for precision and consistency, making it suitable for competitive shooting. This type of ammunition undergoes stringent testing to ensure tight tolerances in manufacturing. The high-quality brass, meticulously measured powder, and precisely engineered bullets provide superior ballistic performance.

Types of Bullets

Bullets come in various types, each designed for specific purposes:

Know Your Caliber Precisely

Similar calibers, such as 9mm Luger and 9mm Makarov, have subtle differences, and they are NOT interchangeable.

Common Calibers

Many calibers are made for firearms, but the most common are 22LR, 9mm, 10mm, .223/5.56, and .308. Here are some of the most common:

Ammo Size: Caliber vs Gauge

Caliber and gauge are two different ways to measure the diameter of a firearm's barrel bore.

Caliber refers to the internal diameter of the barrel bore for rifles and handguns. It's typically expressed in inches or millimeters.

• US Firearms makers use hundredths of an inch: .22, .45, etc.
• Makers in countries other than the US use millimeter measurements: 9mm, 5.56mm, etc.

The caliber represents the nominal diameter of the bullet that the barrel is designed to fire. The actual bullet diameter is slightly smaller than the bore size to allow for clearance.

Gauge is an older British measuring system used specifically to measure the bore diameter of shotguns. It is the opposite of caliber. The larger the gauge number, the smaller the bore diameter.

The gauge number represents how many lead balls of the bore diameter it would take to make one pound in weight. For example:

• A 12-gauge shotgun has a bore diameter such that 12 lead balls of that same diameter would weigh 1 pound.
• A 20-gauge shotgun has a smaller bore diameter, where 20 lead balls of that diameter would weigh 1 pound.

So, a 12-gauge shotgun has a larger bore diameter than a 20-gauge shotgun. The exception is the .410 shotgun, which is measured like a caliber at .410 inches in bore diameter.

You can determine what caliber a firearm needs by checking the receiver or barrel for a stamp.

• Barrel Stamp - Most modern firearms have the caliber or gauge stamped on the barrel. For rifles and handguns, this is often found on the side of the barrel or slide. The gauge for shotguns is usually stamped on the receiver end of the barrel, often on the left side.
• Receiver Stamp - some firearms may have the caliber stamped on the receiver.

Grain Weight & Velocity

Grain weight and velocity are two crucial factors that significantly impact a bullet's performance. These terms are often seen on ammunition boxes, but their importance is sometimes overlooked.

Grain weight refers to the unit of measurement used to specify the weight of a bullet or projectile. One grain is equal to 1/7000th of a pound or approximately 0.0648 grams. This ancient unit of measure dates back to using wheat grains to measure small weights.

Bullet grain weights can vary significantly, even within the same caliber. For example, 9mm Luger ammunition can have bullet weights ranging from 115 grains to 147 grains or more. The higher grain weight produces a heavier bullet.

Bullet weight plays a crucial role in several aspects of a bullet's performance:

• Recoil - Heavier bullets (grain weight of 125 or greater) generally produce more recoil than lighter bullets when fired from the same gun. This is due to the increased momentum imparted to the gun during the shot.
• Trajectory - Lighter bullets (grain weights below 125) tend to have a flatter trajectory and less drop over long distances compared to heavier bullets of the same caliber. However, heavier bullets are less affected by wind drift.
• Penetration - Heavier bullets typically have better penetration capabilities due to their increased momentum and sectional density (the ratio of the bullet's weight to its diameter).
• Terminal Performance - The bullet's weight, combined with its design (hollow point, full metal jacket, etc.), affects its performance upon impact with a target. Heavier bullets generally transfer more energy to the target.

Bullet velocity, measured in feet per second (fps), refers to the speed at which a bullet travels after leaving the muzzle of a firearm. Velocity is primarily determined by the amount of powder used and the barrel length of the firearm.

Higher velocities generally result in flatter trajectories and increased energy transfer to the target. However, in some situations, excessive velocity can also lead to increased recoil and potential over-penetration.

The relationship between bullet grain weight and velocity is inversely proportional. For a given amount of propellent, lighter bullets will typically have higher muzzle velocities than heavier bullets of the same caliber. This is because the lighter bullet requires less force to accelerate to a higher speed.

Choosing Ammunition

When selecting ammunition, it's essential to consider the intended application and balance the trade-offs between grain weight and velocity.

Match Your Ammo to its Intended Use

Hunting and defense rounds are too soft and expensive to waste at the practice range. Training rounds are too hard to be effective in hunting or defensive situations. Full metal training rounds are better suited to hitting steel targets. While it may seem excessive to buy multiple types of ammo, one for practice and one for hunting or defense, you'll save yourself in the long run.

Target or Plinking

Accuracy is the most important factor in target shooting. FMJ bullets are commonly used because they are cost-effective and provide consistent performance. Lighter bullets with higher velocities and flatter trajectories may be preferred for long-range target shooting, while heavier bullets can provide better recoil management for practice sessions.

Self-Defense or Home Defense

Self-defense ammunition needs to have the best stopping power. Hollow points expand on impact, providing enough penetration to affect the target without over-penetrating or affecting bystanders. Moderate to heavy bullets with reliable expansion and penetration are favored for self-defense situations.

Hunting

Hunting ammo must deliver effective terminal performance, which means it should expand and penetrate adequately to ensure a humane kill. Soft points and hollow points are designed for controlled expansion and deep penetration. You'll want to choose a caliber and grain weight that will be effective for the size of game you're going after. Small calibers are effective for small game, while larger calibers are more effective for large game. Don't forget to check your local regulations for recommendations and restrictions.

Storage and Handling

Ammunition should be stored in a cool, dry, and well-ventilated area away from direct sunlight, heat sources, and moisture.

Ideal Storage Conditions

The ideal temperature range is between 60 and 80 degrees Fahrenheit or 15 and 27 degrees Celcius. Extreme temperatures can degrade the propellant and affect the ammunition's performance. Humidity should be kept below 70 percent to prevent moisture buildup, which could cause damage. Proper ventilation helps prevent fume buildup, which could be flammable. Keep it separate from other flammable materials and store it in a secure location to prevent unauthorized access.

Ammunition Shelf Life

Modern ammunition can be stored for up to 20 years under ideal conditions. However, due to propellant composition changes, ammunition produced before 1990 may have a shorter shelf-life. It's important to regularly inspect your ammo for signs of degradation, such as corrosion, discoloration, and deformation. If you notice any issues, it's best to safely dispose of the affected ammo.

Safety Precautions

1. Always handle ammunition like it is live, even if you believe it isn't.
2. Store ammo separately from firearms to prevent accidental discharge.
3. Never mix different types or calibers, which can lead to dangerous situations.
4. Carefully inspect each round for signs of damage or defects before loading it into a firearm.
5. Dispose of damaged, corroded, unwanted ammo at an authorized facility.
6. Always follow the manufacturer's instructions for safe handling, storage, and use of ammunition.