What Is Grain Weight in Bullets?

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If you’re a new gun owner purchasing ammunition, you might have noticed the word grain along with some numbers on an ammunition box. This refers to the grain weight of the ammo. Are you curious to know what is grain weight is in bullets?

What Is Grain Weight in Bullets?

The weight of a bullet is commonly measured in grains using a balance. A pound is equal to 7000 grains. An ounce is equal to 437.5 grains. The weight of the bullet can indicate the type of cartridge that may have contained the bullet.

A man reloading bullets

However, the bullet should be relatively intact. Grain weight is one of the factors that determine cartridge type used commonly by law enforcement and forensics.

Grain Weight and Cartridge Type

Below is a table consisting of popular small calibers and their corresponding grain weight.

17 Remington25
22 Short27 – 30
22 Long Rifle36 – 40
22 Win Mag30 – 50
25 ACP 45 – 50
7.62 Tokarev84 – 92
7.65 (30 Luger)90 – 96
32 S&W85 – 88
32 – 20 WCF90 – 115
32 Short Colt80
32 Long Colt82
32 S&W & 32 S&W Long95 – 100
32 Auto60 – 71
8mm Nambu99 – 103
380 Auto85 – 102
9mm Parabellum88 – 147
9mm Makarov90
9mm Steyr114 – 118
9mm Mauser123 – 128
38 S&W145 – 150
38 Long Colt/Colt New Police148 – 150
38 Special95 – 158
357 Magnum110 – 180
38 Auto115 – 147
40 S&W141 – 180
10mm Auto155 – 200
41 Rem Magnum170 – 240
41 Short Colt160 – 167
44 Rem Magnum180 – 275
44 S&W Special200 – 246
45 ACP175 – 230
45 Colt225 – 255

Is Heavier Better?

Heavier grain weight has its own advantages. Most people choose to use heavier bullets because they want better expansion and penetration. Expansion and penetration are also affected by other factors like:

  • Bullet shape
  • Material
  • Distance
  • Muzzle velocity
An image of bullets

Pros of Lighter Grains

  • More speed. The better the speed, the straighter your trajectory will be for high-accuracy shots. This is why lighter bullets are great for long-range shooting.
  • Because of its high accuracy, lighter bullets are favored in competition shooting where accuracy is measured.

Cons of Lighter Grains

  • Lighter bullets mean that they can be influenced by wind. Strong winds could easily affect the trajectory and accuracy of your shots using lighter bullets.
  • Lighter bullets deal less damage to the target. If you want to kill a pest or game humanely, you may want to use heavier bullets so they don’t suffer.

Pros of Heavier Grains

  • Heavier bullets are likely resistant to the wind so they are more accurate in windy weather.
  • Heavier bullets have better power and penetration on impact.

Cons of Heavier Grains

  • Heavier bullets aren’t great for long-distance shooting.
  • Heavier bullets can generate strong recoil. This may be unique for each shooter since recoil management varies with people.
Bullets on a black surface

Related Questions

What Is a Good Grain for a Bullet?

It depends on your personal preference. The most commonly used grains for bullets are 55-grain for 223 Remington and 115-grain for 9mm Luger. This could be a standard start point for a beginner.

Why Are Bullets Weighed in Grains?

Grains are also a part of the unit measurement of mass. The weight of the grain is extremely small. So if you use grams or kilograms, you would have to write a lot of numbers.


Knowing grain weight in ammunition is helpful. There are certain grain weights that you might want to choose for certain calibers if you want to get the best ammunition. You also don’t want to make the wrong purchase because you don’t know what grain weight means.

James Forrester is a lifelong gun and firearms owner, and an even bigger advocate for gun safety. He created KeepGunsSafe.com with the purpose of sharing helpful tips and educating others on how to keep guns and weapons safe and secure.