Shooting Mystery is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

What Does Grain Mean in Ammo? — Bullet Grain EXPLAINED

What Does Grain Mean in Ammo

If you’re a new gun owner picking up your first bullets, or even if you’re an experienced shooter out on the field, bullet grain might be an unknown aspect about ammunition for you.

When picking up a box of ammo, most firearm users tend to look at the caliber of the bullets and call it a day.

And that’s actually fine. But learning about the bullet grains or the different bullet weights will give you an ADVANTAGE when it comes to shooting.

So let’s take a look at what exactly a bullet grain is.

What Is Bullet Weight/Bullet Grain?

In simple terms, the bullet grain is a unit for weight measurement.

To put things in perspective we compiled a list of items and their weight in grains (gr).

  • A paper clip = 15.43 gr
  • A nickel = 77.16 gr
  • an iPhone X = 2,685 gr

So if you thought the bullet grain had something to do with the gunpowder, it has nothing to do with that.

How Does the Weight of the Bullet Affect Shooting?

So now that you know that is basically a unit of measurement for mass, how does it affect shooting?

The bullet weight will affect a lot of factors when you shoot such as the felt recoil from your firearm, the overall speed and trajectory of your bullet, and the velocity of your bullet as it leaves the gun. Bullet weight MATTERS.

Let’s take a look at a few factors that the bullet weight affects.

Recoil

Recoil Icon

When you begin working with guns, you’ll most likely remember a lesson from your science class.

“To every action, there is an equal and opposite reaction.”

When you shoot a round with your gun, you’ll most likely feel the recoil from your shoulder.

Bullet weight comes to play an important role here.

If you use lighter bullets, some shooters describe the lighter recoil as having a “snappy” feeling. On the other hand, some shooters say that heavier bullets have a “pushy” feeling.

However, there’s no way to determine how the recoil will feel just from the bullet grain. For example,

  • If your ammunition uses slow-burning powder, you probably won’t feel the recoil all at once.
  • But if you use a fast-burning powder, you’ll most likely be able to feel the recoil hit you all at once, making it more noticeable.

Use different weight grains to find out which grain you like the best.

Muzzle Velocity

Muzzle Velocity Icon

To put it in simple terms, muzzle velocity is the speed at which your bullet leaves the barrel. In the U.S. it’s measured by Feet Per Second (FPS).

You might think a bullet with heavier grain size is better than a lighter grain bullet—that assumption is wrong.

Lighter bullets are found to leave the barrel of a gun with higher FPS rates than heavier bullets.

So what? Well, the higher your muzzle velocity, the more it stays in TRAJECTORY and can hit your target with more ENERGY.

In our comparison article about the .38 Super and .38 Special, the .38 Super is a great example of a bullet with high muzzle velocity.

Speed & Trajectory

Speed & Trajectory Icon

If you’re the type of shooter who likes to get a lot of range when you’re out shooting, having the right bullet weight definitely matters.

See, because the weight of a heavier cartridge tends to attract more gravity, the range it travels might be lacking.

A lighter bullet weight will cause your ammo to travel farther. A lighter projectile will have a flatter trajectory and straighter trajectory than a projectile with more mass.

Subsonic

Subsonic Icon

Do you hate the sound of guns but still want to shoot a few rounds?

Subsonic ammunition will be your best friend in that case. They’re made to travel at speeds slower than the speed of sound and if they’re paired with a good sound suppressor, they’ll make MINIMAL NOISE.

A caliber like a 45 Automatic Colt Pistol (ACP) will use heavier bullet ammunition which makes them subsonic. Ammo can only be subsonic if they’re heavier than what the caliber calls for.

Another cool thing about subsonic ammo is that if you use it with a quality suppressor, it also lessens the felt recoil because it absorbs the energy quite well.

When to Choose a Heavier Bullet or a Lighter Bullet

Your needs will change depending on the purpose of your shooting.

If you’re out hunting for deer, participating in target shooting sports, protecting yourself from a perpetrator, or just long-range shooting for pleasure at a range, the ammo you choose to use will also change.

Hunting

Hunting Icon

Heavier bullets are preferred when hunting. A heavier bullet has better expansion and penetration when hitting a live target.

That way, it kills the target faster in a humane way.

Of course, the right bullet weight isn’t the only thing to consider when choosing your bullets for your next hunt.

For example, you might want to take a light hollow point bullet (HP bullet) over a heavy full metal jacket bullet (FMJ bullet). This is because a hollow point bullet expands upon impact, staying inside your target.

You might also want to invest in some SPECIALTY ROUNDS when hunting specific animals.

Self-Defense

Self-Defense Icon

If we’re talking self-defense, you might want to settle for heavier grain weight bullets.

More weight means it improves “terminal ballistics” or the way the bullet transfers energy into the target.

Basically, a heavier bullet could be better for self-defense since it has a greater chance of stopping your threat.

However, you should also take note of other factors like the gun itself and the caliber and NOT JUST the bullet weight.

Distance Shooting

Distance Shooting Icon

When it comes to distance shooting or long-range rifle shooting, you’ll find that a lighter bullet suits you well.

This is because a light bullet can carry over long distances and is generally faster than a heavy bullet.

Some people say that lighter bullet grains are far more accurate than heavier bullet grains, but that really depends on the wind.

If you’re shooting a round at a range on a windy day, a light bullet can easily travel on a different course because of the wind.

Still, lighter bullets are favored by distance shooters.

Of course, this varies from person to person, from rifle to rifle so be sure to test the ammunition you pick up.

Accuracy Shooting

Accuracy Shooting Icon

If you’re doing precision shooting for target shooting sports like bullseye shooting, bullet weight isn’t the only thing you should be looking at.

For some reason, some guns prefer different bullet weights over other bullet weights. This will affect your accuracy for better or for worse.

That means there isn’t a better bullet weight for maximum accuracy.

The only way you can find out what suits you best is by TRIAL AND ERROR. It doesn’t hurt to ask other shooters their opinions, though.

However, aside from bullet weight, your maximum accuracy will also depend on barrel length, muzzle velocity, muzzle energy, twist rate, and a ton of other factors.

Plinking

Plinking Icon

If you’re only out to a range to do some plinking, bullet weight doesn’t really matter.

Plinking isn’t something you do seriously so you don’t need to look at the accuracy or speed of your cartridges.

What to Look for When Buying Ammo: Guns and Ammunition

As we said, bullet weight doesn’t hold up much if you disregard other factors when choosing your bullets.

So we’ll go through what else you need to look out for when picking up a box of ammo.

Your Gun

Your Gun Icon

Your gun will usually dictate your bullet weights.

For example, an AR-15 has an average bullet weight of 55 gr. However, you can still find ammunition with bullet weights that range from 40 gr to around 70 gr to go rifle shooting.

Likewise, a 45 mm gun has an average bullet weight of 230 gr but you can easily find ammo for it with grains of 155 grains to 200 grains.

Bullet Size & Caliber

This might seem like a no-brainer but you need to pick ammunition that has the same bullet size as your gun’s caliber.

If you’re unsure what the caliber of your gun is, you can check the barrel of your firearm where it will be indicated.

Cartridges for 9mm guns won’t fit in a 45mm gun so be careful when you buy your bullets.

Bullet Types

Bullet Types Icon

Ammo comes in different kinds and we already mentioned two types in this article: the Full Metal Jacket bullet and the Hollow Point bullet.

We’ll go through each kind of ammunition as simply as we can.

Full Metal Jacket Bullet (FMJ)

Like the name suggests, it’s completely wrapped in a metallic encasing.

They can be pointy, round, or flat.

This kind of ammunition is favored when shooting in a range. That’s because if used for self-defense, the bullet can create an exit wound and cause collateral damage.

Hollow Point Bullet (HP)

A hollow-point bullet isn’t completely wrapped like an FMJ bullet.

Because they expand, it doesn’t go through the target which makes it popular for hunting and self-defense.

Open Tip Bullet (OTM)

Open Tip Bullets are often used in shooting matches where accuracy is highly needed.

They’re designed to be perfectly balanced which is why distance and target shooters like them so much.

That’s why this type of ammo is also referred to as Open Tip Match bullets (which is why it’s abbreviated as OTM).

Ballistic Tip Bullet

These bullets work similar to a hollow point bullet but they offer MORE DISTANCE and ACCURACY than an HP bullet.

We mention this in our 6.5 Creedmoor vs 7mm-08 Comparison Guide if you’re interested to learn more.

Soft Point

Soft Point bullets are similar to Ballistic Tip bullets except for the fact that the tips are hollow. This allows for even better expansion.

However, Ballistic ammo outperforms Soft Tip bullets most of the time.

Your Preferences

Your Preferences Icon

This might be the most important thing on the list because ultimately, the person shooting is you.

With all things you’ve learned from this article, you’ll have to apply it to your needs and wants. You might find that working with a lighter bullet suit you best even if other shooters say otherwise.

You’ll have to test out different kinds of cartridges and find out which one you feel like you perform the best with.

Parts of a Bullet

Now that we’ve gone through all of that, let’s return to the basics.

Here are the parts of your ammunition.

Primer

This is the bottom part of your cartridge. It’s struck by the firing pin to cause an explosion by the powder.

Gunpowder

This is the power behind the bullet. When the powder is ignited by the primer’s power, it creates the gas that propels the bullet out from the cartridge.

Bullet

This is the projectile that leaves the cartridge.

It’s probably the most well-known component of a cartridge since that’s usually what you see pass through your intended target.

Case

This is the metal casing that holds everything together in a cartridge. These can also be called shells or brass.

When talking about bullets, some people will call cartridges the bullet, when it’s really the entire component of your ammunition.

FAQs

What Does Higher Grain Ammo Mean?

You might see that some people talk about higher grain ammo. Don’t worry, there’s nothing else you need to know about bullet weight.

Higher grain means using heavier grain bullets.

On that note, lower grain means that it’s lighter grain bullets.

What’s the Difference Between 115 Grain and 124 Grain 9mm Ammo?

Oh boy, this is quite a question.

The difference between the bullet weights might seem minimal—after all, it’s a 9-grain size difference. That’s about less than a fraction of a pound.

However, there is a difference especially when you’re actually shooting with your firearm.

If you fire a round or two with a 115-grain bullet, you might notice that the recoil doesn’t feel as harsh compared to the recoil with a 124-grain bullet.

It’s also due to the size that you feel the difference.

It also performs differently when it enters the target. The more mass there is packed in the bullet, the more energy it has to transfer.

In the end, it also boils down to which kind of ammo you prefer.

Where Can I Find the Bullet Grain Number?

You can easily find the bullet weight of your ammunition on the side of the ammo box it comes in.

It will be written like 115 grains but if you can’t find it on the side of the box, you can search the kind of ammo you bought online and it should come up.

Final Thoughts

Bullet weight isn’t the end game of all things you need to know about guns and shooting but it certainly helps to know about it.

It’s an aspect of your cartridge and it can help you when you’re out there shooting, whether it be in a competition, in a hunt, or when you’re in need of self-defense.

It’s also a bonus if happen to come by some shooter at your local range asking “What does bullet grain mean?” you got them covered!

About the author

Christopher Wade

Christopher Wade is a true outdoorsman. After spending most of his career as a firearms expert and instructor in Nebraska, he retreated to the great outdoors to enjoy retirement.

Christopher’s expertise in handling firearms and hunting gear are what propelled him to create the Shooting Mystery blog. He hopes for all readers to gain useful and practical knowledge for enjoying their time outdoors.