How to Choose Bullet Weight – What You Need to Know

Most gun owners don’t need to be experts on bullet […]

Sure, you know the caliber of the firearm, you may even know the general distance and speed

Sure, you know the caliber of the firearm, you may even know the general distance and speed

Most gun owners don’t need to be experts on bullet weight

However, learning about weight; about how it impacts speed, accuracy, and terminal ballistics, will make you a more knowledgable and confident shooter

In the end, this will increase your enjoyment of shooting sports and allow you to select better ammunition for your specific needs

A Primer on Bullet Weight

What Does Bullet Grain Mean?

To start this discussion, let’s begin with an explanation of the basic unit of measurement for bullet weight: grains

You will often see bullets listed with the grain size before the bullet type

For example, 9mm rounds may be listed as “115 gr FMJ” This tells us that the cartridge is loaded with full metal jacket bullets that weigh 115 grains

As you learn more about ammunition, you will find that cartridges have a wide range of bullet sizes

The smallest commonly-used bullet size is likely 15 grains, which is found in some 17 HMR cartridges

However, you can find cartridges with bullets over 600 grain, which are found in products for the 50 BMG

Most Cartridges Have a General Range of Bullet Weights

Bullet size within a given cartridge can vary, but there is a general range of size for each ammunition cartridge

For example, AR-15 ammunition has a standard size of 55 grains, but you can purchase ammo for your 223 rifle with bullets ranging from below 40 to over 70 grain

Likewise, 9mm Luger cartridges have bullets from 60 to 160 grains

The point is that even when you purchase a given firearm to shoot a specific cartridge, you still have options for bullet size

How Does Bullet Grain Weight Impact Shooting?

Bullet weight makes a difference on how the bullet performs

It will impact how the firearm recoils, and it will have an impact on the overall trajectory of the bullet

Finally, it will impact terminal ballistics, changing how the bullet performs once it strikes a target

When thinking about bullet weight, it’s important to think about how you will be using the cartridge

If you are simply “plinking,” that is, casually shooting smaller cartridges at a short to medium distance, weight is not really a concern for you

For most plinkers, you’ll simply want to purchase the ammunition that best fits your budget

If you are shooting for maximum accuracy, however, the bullet weight matters, but it’s not as simple as saying heavier or lighter bullets are better

Here’s what we can say: a lighter bullet generally has greater speed, which means it can often maintain a straighter trajectory at a greater distance

However, a light bullet delivers less energy and is susceptible to wind, which means it can be blown off target much easier than heavier bullet

To understand these points, let’s look at two products from Federal Ammunition

We took some of their most popular self-defense ammo for 9mm pistols, HSTs in 124 grain and HSTs 147 grain

This ammo is the same brand, line and is even loaded with the same bullet

So, what does a 23 grain differential mean for muzzle velocity?

So what, it’s still a bullet speeding at about 1,000 feet per second and that’s going to hurt, right?

The five shot average muzzle velocity for the lighter 124 grain bullet is 1073 feet per second

When you calculate the muzzle energy for this bullet, you come up with 317 foot pounds

The five shot average muzzle velocity for the heavier 147 grain bullet was just under 940 feet per second

If you’re a believer in muzzle energy and the idea of putting as much energy into your target as possible to stop a threat, this bucks the trend that “bigger is better” when it comes to bullets

In this case, the lighter bullet, moving faster delivers more energy

Bullet Weight & Recoil

Physics dictates that bullet grain will play a role in recoil

We know it requires more energy to move a heavier bullet than a lighter bullet, right?

Well, when we consider that for every action there is an equal and opposite reaction, we know a heavier bullet generally means more recoil than a lighter bullet

In the case of HSTs, we’d actually expect more recoil from the lighter bullet though because there is more energy pushing out of the barrel

For example, if you’re using a large frame pistol, that firearm might help absorb some of the recoil, reducing what you feel

A good example of this is the relatively short-cased 40 S&W cartridge

It’s not uncommon to refer to a 40 cal round as “snappy” when compared to larger cartridges, like 45 ACP

The most important reason to select a larger bullet is energy at the target, which improves “terminal ballistics” Basically, if you want better expansion and penetration you will likely want to choose a heavier bullet

(Both expansion and penetration are affected by bullet shape, material, and other factors as well, but weight plays a role )

This essentially means that in most cases heavier bullets are reserved for hunting and self defense

When loaded into hunting rifles, a heavier bullet is more likely to deliver more energy into the target, resulting in a more humane shot

For self defense, a heavier bullet gives you a better chance at stopping a threat

Choose A Lighter Bullet Grain If…

A smaller bullet can be effective if overall speed and distance is your goal

Speed is generally preferred for distance target shooting, as it reduces the chances of drop

As we saw above, the heavier bullet dropped further, which means your trajectory will be straighter with a lighter projectile, and your overall distance potential will be longer

If you participate in distance rifle shooting, especially for target practice, a lighter bullet may be ideal

If you are hunting with a rifle at long distances, a light bullet may be better, but you will sacrifice energy

Smaller bullets can also reduce recoil

If you carry a pistol and have difficulty handling high recoil, you may find that a smaller bullet is more comfortable to shoot

Final Thought: Start “Standard” Bullet Grain & Go From There

If you are not sure whether you should go with a heavier or lighter bullet, the best option is to go with something in the middle

Many calibers has a standard bullet weight, such as the 223 Remington with a 55-grain bullet

Others have weights (or a narrow range of weights) that are most common because they deliver the best performance

For example, the 9mm Luger is most commonly found with 115-grain, so this is likely your best starting point

Find the Right Bullet Weight for Your Needs at Ammo To Go

Want to find a variety of cartridges and search for different bullet weights for your specific needs?

Here at Ammotogocom you can select the cartridge type, then filter your search by bullet weight, type, or even brand

For the average shooter, reading the description on a box of ammo can make it feel like you’re deciphering a secret message

Ammo comes in many different flavors and between the terminology, abbreviations, and numbers, it can be overwhelming to figure out what it all means and bullet weight is just part of that formula

The first section is an explanation of what bullet weight is

Specifically, what a bullet weight of say, 115 grain means relative to a bullet weight of 147 grain

The second section of this article contains tips for using bullet weight to your advantage and how to adjust bullet weights to maximize your potential ability to remain on target

We frequently get questions about what all these descriptors on the box mean, and one of the most common questions is what “grain” is and what you should be shooting

We’ll get to the latter in a minute, but first let’s get an understanding of what grain actually is

What is Bullet Weight / Grain?

A grain is a unit of measurement of mass

4375 grains equals one ounce

When you see “grain” (sometimes abbreviated as “gr” or “grs”) preceded by a number on a box of ammo, it is referencing the weight of the bullet

This isn’t the weight of the entire round of ammunition, but just the projectile that leaves the barrel

A common misconception is that the grain information on the box is referencing the powder found in a cartridge

There are all sorts of slang terms for a round of ammunition

For instance, in casual conversation a cartridge may be referred to as a bullet

In actuality, a single round of ammunition is made up of four basic components, with the bullet being just one of those elements

If you are not familiar with the composition of a cartridge, here’s a quick explanation of these four parts:

Primer: The part of a cartridge that is struck by the firing pin, creating a small explosion that ignites the powder

Powder: Fast-burning propellant that is ignited by the primer explosion; the gases released create a pressure in the case that pushes the bullet out

Bullet: The projectile that leaves the barrel of the gun and moves toward your target

Common Bullet Weights

Two different 9mm bullet weights and types: 147 gr

Within each caliber, you will notice that there are certain bullet weights you see more often than others

How does bullet weight affect shooting?

So now we know that there are different weights for bullets and that this is measured in grains, but what does it mean for the shooter?

Well, the weight of the bullet affects its performance once fired, including effects on recoil and accuracy

Recoil– The big debate is whether bullet weight affects recoil

Because there are so many factors that contribute to recoil, we can’t determine how bullet weight alone impacts it

Instead, we have to understand the relationship between bullet weight and recoil

Power factor is a measurement of the momentum of the bullet and is used primarily in competition settings to determine perceived recoil

It is calculated by multiplying the bullet weight by the velocity, then dividing by 1,000

Two different rounds could have different bullet weights and different velocities, but equal the same power factor

Theoretically, cartridges with the same power factor have the same recoil, though this isn’t always true and we need to look at the other factors involved

Lighter bullets must travel faster than heavier bullets to reach the same power factor and therefore require more gunpowder

This means that the lighter bullet will spend less time in the barrel than the slower moving heavy bullet, causing a difference in perceived recoil

Many shooters say that the light, fast bullet seems “snappier” while the heavy bullet’s recoil is more of a flat push

Other factors that can alter perceived recoil include barrel length, gun weight and design, and the shooter’s grip and stance

With all these variables, it’s near impossible to definitively say which bullet weight has the most effect on recoil

Accuracy- In general, you may find that your gun performs with better accuracy with a certain bullet weight

This can differ from gun to gun and experimenting with different rounds is the best way to figure out what works best for you

A heavy bullet may be less likely to be affected by external conditions such as wind, but it also may be harder to stabilize resulting in keyholing, or the bullet entering the target sideways

When should you worry about bullet weight?

Your intended use is important and will help to determine what cartridge is best

Range Training- There are many shooters who have never paid any attention to bullet weight

Shooters who just want to plink at the range can usually find an affordable round that consistently makes both their gun and wallet happy

Self Defense- If you’re choosing a self defense round, bullet weight should not be your initial concern

Bullet penetration and expansion are far more important than weight when selecting a round that will be used on targets other than paper and steel

Since the point is to stop a threat, you want ammo that travels deep enough into the target to hit vital organs while expanding enough to not leave the body and cause collateral damage

Tac-XP +P hollow point rounds pictured above are a popular self defense option

There are people who swear by a heavier bullet weight in their self defense rounds and it is true that certain brands and product lines have better track records than others

You may find a lighter bullet has performed consistently better than a heavy bullet in a ballistic testing (or vice versa); because of all the factors involved, relying solely on bullet weight is unrealistic

Take a look at the Federal Bureau of Investigation – it recently selected Hornady Critical Duty 40 S&W 175 grain as its official ammunition even though there are defensive rounds available in heavier and lighter bullet weights

Features such as the no-clog hollow point bullet and a design and powder load specifically for use in a full size handgun contributed to the decision as well as consistent performance in testing

Ultimately, find a cartridge that performs well under testing or real world applications and most importantly, one that functions well in your gun

Some guns just don’t like certain cartridges and you want to know what your gun likes before you need to use it

Hunting- Picking out a round for hunting follows the same line of thinking as picking out a round for self defense – you want to stop (in this case, kill) your living target

Again, you need a round powerful enough to penetrate the vital organs of your target

Considerations that need to be taken include the size and anatomy of the game, the terrain, the distance at which you are shooting, and the laws and regulations where you are hunting

Selecting a caliber that is adequate for the game and conditions you are hunting in will be more important than any particular bullet weight

There are specialty rounds available specifically for the game you will be hunting, such as the Winchester Super-X 308 which is designed with a 180 grain soft point bullet specifically for deer and boar hunting

Precision Shooting- When shooting rifles at longer distances, bullet weight becomes more important

Because heavy bullets generally travel at a slower velocity and don’t rotate as fast, they can be harder to stabilize than a lighter, faster moving bullet

Your barrel length and twist rate will play a part in your ammo selection, with heavier bullets requiring a faster twist rate

The science behind long range rifle shooting is vast and confusing, but there are many precision shooters out there who can offer guidance and education on the topic

Competition- Depending on what competition venue and division you are competing in, power factor will probably be important to you and you will need to be sure your ammo is meeting the set requirements

Competition shooters want minimal recoil and the current trend shows shooters that compete with lighter polymer guns lean towards heavier bullets, while those shooting heavy race guns favor lighter bullets

There are many ammo options on the market, and bullet weight is just one of many considerations to make when picking out the right rounds for you

What works well in one gun may not be reliable in another, but by evaluating your needs and implementing a little bit of experimentation, you’ll be able to find the best fit for you and your gun

Practical Tips Dealing With Bullet Weight

Visually, it’s tough to tell them apart but when shooting, most shooters will feel a difference

But there are three reasons why you might want to try a different weight bullet in the caliber you’re shooting

It’s not unusual to be limited to doing no more than hammering the rear sight to one side or the other to shift your hits left or right

If your rounds consistently hit the target higher or lower than you want, then you have two options

By changing the height of a sight, you can make them match the sight picture you’d like to see (your point of aim) for the hole you make on your target (your point of impact)

The easier way, that doesn’t require taking a hammer to your gun or seeing a gunsmith to adjust your hardware, is to try changing the weight of the bullets you’re shooting

You’ll need to buy a box or two of ammo in different bullet weights, then shoot the best groups you can at different distances to see what works best

Perceived Recoil

As you shoot those groups to see how high or low they impact compared to your preferred sight picture, you may notice that all else being equal, ammunition with different bullet weights might feel different in your hands

Lighter bullets traveling faster usually feel “snappier,” for instance

Heavier bullets are often described as having less felt recoil, but perhaps not enough to account for other characteristics of how the gun feels and behaves through the firing cycle

Either way, if you find that you don’t like how your gun feels when you shoot it, changing bullet weights can be an easy way to adjust that

The other characteristic you might notice as you shoot groups for elevation is that you’re getting better or worse groups with different bullet weights, and your gun might be running more or less reliably between ammo types

Some guns, pistol and rifle, just “like” certain bullet weights or even certain specific ammunition types, better than others

There isn’t always any predictability to what that might be, so if you’re looking for maximum accuracy out of your gun, you’ll need to try a wide variety

Even if you’re satisfied with what you’re getting out of your current ammo of choice, it can be worth trying others from time to time to see if you can do better with a different choice

You also might see that ammo with different bullet weights won’t always look alike

One weight might have a more rounded tip while another is more squared off and blunt

While this isn’t always dependent on weight, it’s one factor that can affect the shape – also known as the profile – of the bullet

Certain handguns in particular can be more or less reliable with different profiles

If you have a gun that has trouble feeding what you’re shooting, changing the weight of the bullet in your ammunition can change the profile, and with it, help your gun work better

As you can see, you can change quite a few things about the way your gun shoots without the hassle of making changes to your equipment

For the price of a few boxes of ammunition, you can make your gun shoot to its sights, change how its recoil feels in your hands, and even make it more accurate and reliable

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