Understanding Bullet Grain in Ammunition

There’s a lot of misunderstanding about bullet grain and how it affects the shooting fun you have at the range. To add to the confusion, new or inexperienced shooters might hear reloaders talk about gunpowder grain. Both are subjects that don’t often come up when you’re considering purchasing or building a new gun, where the caliber is the primary focus, both on the weapon itself and the printing on the box of cartridges you pick up to put through it. Whether you’re new to shooting sports or you have a safe full of beauties you bring out from time to time, understanding bullet grain, how it affects the rounds you shoot, and what it means for you as the shooter are important concepts to familiarize yourself with.

What Bullet Grain Means

When we talk about bullet grain, which is usually expressed on the box as a number followed by the letters gr, e.g. 55gr on many .223 caliber rounds fired in AR-15 rifles. In this case, the bullet weighs in at 55 grains, which at 1/7000th of a pound each, is a really small amount of weight. While your gun will happily chamber a round that’s the right caliber, the .223 in the example above, the weight helps you better understand what that bullet is going to do once it leaves the barrel of your gun and impacts your target. 

The Nitty Gritty On Grain Weight

Grain weight is another measure of mass, similar to the ounce, pound, or gram. It is a very precise measurement, however, with 7,000 grains equalling one pound. While we wouldn’t want to see that number reflecting our weight when we step on the bathroom scale, it’s a great way to keep track of small objects that need an exact measurement of their mass, like bullets or the gun powder charge that ignites, expands, and pushes them out the end of your gun’s barrel.

To clear up a few definitions, what is commonly referred to as a bullet–the things you load into your pistol’s magazine one by one–is actually the cartridge. The cartridge consists of a metal casing (the brass you police up after shooting), a small amount of propellant that’s held inside the casing, a primer that your gun’s firing pin or hammer hits to ignite the powder, and the rounded or pointed end, which is the only part of the cartridge that is technically the bullet. Understand that bullet grain–the weight of the actual bullet that the cartridge is loaded with–is the grain weight printed on your ammo box.

The propellant is also measured in grain weight, but for most shooters, gunpowder grain isn’t something you need to be concerned with. Handloaders who reload brass to make their own cartridges will factor it in when planning their rounds–usually using a powder charge of 5 grains or less. If you’re concerned about a cartridge’s velocity or muzzle energy, most manufacturers print them on your ammo box directly in a far easier to read format than providing powder grain and expecting you to do the math.

Ugh. Who Cares!? Pull Trigger, Gun Goes Bang Is Enough!

You care because bullet grain affects the results of your gun going bang. Bullets come in a range of weights that make some bullets better for a particular task than others. In general:

• Heavier bullets go slower, shoot straighter, and deliver energy better.
• Lighter bullets travel faster, move farther, and have less-efficient energy delivery.

Where Heavy Comes In Handy

There’s a lot to be said for higher grain bullets, and physics does the talking. You may remember from junior high science that objects at rest stay at rest, objects in motion stay in motion, and both keep on keeping on until an outside force makes them do something else. The heavier the object, the more force that’s needed to influence its velocity or trajectory.

• Wind-Resistant – At an indoor range, you don’t need to worry about crosswinds. In the field, you do. Heavier bullets move less when the wind hits them from the side, and they lose less velocity firing into the wind when compared to lighter rounds.
• More Force Delivery – More mass means more force. Higher bullet grains take more energy to get moving, which is translated through the weapon to the shooting platform, which is your burly shoulders and arms. That may not seem like a benefit, especially during rapid-fire exercises when you need to get back on target efficiently between each round, but at the other end of the range, there’s more force delivered to the target, making heavier bullets a popular choice for hunters.
• Low and Slow – Heavier bullets move slower. If they travel slow enough, they drop below the sonic threshold that gives firearm rounds a characteristic crack. Many subsonic rounds are among the highest bullet grains made for their caliber, making them perfect for use with suppressors.

Moving Light and Fast

That doesn’t mean Heavy is always the best. The same gunpowder grain igniting behind a smaller bullet will push it to higher speeds. Gravity works the same on bullets once they leave the gun, regardless of their mass, so the drop rate is consistent, causing the higher velocity to impart a few benefits to the projectile as it travels.

• Longer Ranges – The higher velocity means rounds with low bullet grain travel farther before their trajectory destabilizes or they drop to the ground. 
• Increased Accuracy – A faster velocity means less time in flight between your gun and the target. That’s a shorter duration for wind, gravity, and other factors to act on its trajectory. When combined with the increased effective range, this makes lighter bullets popular for long-range marksmanship.
• Less Recoil – Lighter bullets have less energy to deliver than their heavier counterparts, which means recoil is much more manageable. This makes it a popular target and range ammunition, especially for customers using our Model G Pull Release Trigger, which allows a higher rate of fire by shooting a single round on each trigger action, both pull and release.

What’s The Most Fun For My Money?

That’s a good question. After all, it’s the one that led us to create a low-cost alternative to other “binary” type triggers on the market. Our customers work hard for their money and don’t want to spend the price of another gun adding specialized slides and modifications when a simple drop in trigger group will get the job done with their existing Glock-compatible components. We believe in delivering the most bang-bang for your buck and the most legal fun you can have at the range with your handgun.

If rock’n’roll is your goal, lighter bullet grain ammunition works well with the Model G to deliver round after round with less recoil and more fun. That being said, if heavy is all you have on hand, our trigger group is precision-engineered to work with any ammunition your gun will chamber and fire. Make your next range experience pop with the right bullets and a new trigger from PR Triggers.