This may seem basic to some shooters. However, the number of calls we get referring to this little misnomer may surprise you. When buying factory ammunition, referring to bullet grains has nothing to do with how much gunpowder the cartridge has. The term “grains” refers to the projectile’s mass or weight.
A grain is a small unit of measurement where there are 437.5 grains in an ounce. Therefore, if you were to purchase a box of .223 Remington Brown Bear 55-Grain FMJ, the “55” refers to the mass of the bullet itself, not the entire cartridge — just the projectile.
Some of the confusion comes from the manufacturing and loading of cartridges. Many use bullet grains as a unit of measurement when loading propellants in ammunition, so technically, those who say that bullet grains refer to the propellant are partially correct. However, on a box of ammunition intended for purchase, the grains advertised almost always refer to the projectile’s mass.
The term grains drew from the approximate unit of mass in one seed of cereal such as wheat or barley. Although no longer recommended, medical practitioners still use grains occasionally as part of the apothecaries’ system, especially in prescriptions for older medicines such as aspirin or Phenobarbital.
Why are bullet grains important?
So, why should you care how many grains your projectile weighs? Bullet weight affects the way it flies and how it performs when it hits its target. A heavier bullet travels slower but hits with more momentum, while a lighter bullet has a flatter trajectory and greater velocity.
There is still much debate on how many grains are better for a particular purpose. For defensive ammunition, some people go with a heavy-grain hollow point, while others prefer a lighter, faster bullet. I would encourage you to keep in mind that putting a round on target is far more important than how many bullet grains it carries with it.
Unless you are precision target shooting, hunting animals from great distances, or you are a career military or law enforcement sniper, then just go with the manufacturer’s recommended use for the round in question — it usually says it right on the box.
For defensive purposes, my .45 ACP bullet of choice is Speer Gold Dot 230-grain ammunition. I like other brands too, but this has been my choice for years, and I trust it as reliable ammunition. Shameless plug aside, I practice and train often with this load, and consequently, I know exactly how it shoots in my gun.
Remember, in addition to plinking or practice ammunition, you need to practice the way you’d fight. If you spend months becoming a proficient shooter with inexpensive target ammunition, you may find your gun performs differently with self-defense ammunition. This is not something you want to learn while trying to defend yourself.
Full metal jacket, which means the manufacturer encased the projectile in a hard metal exterior. The jacket allows for higher muzzle velocities than bare lead without leaving significant amounts of metal in the inside of the barrel.
FMJ bullets do have some disadvantages. Soft tip or hollow point bullets expand upon impact, whereas FMJ ammunition does not. This lack of expansion causes less damage to soft targets such as animals and people.
However, since FMJ bullets tend to penetrate hard targets more efficiently, the FMJ bullet is better suited for military applications, where shooting through armor and barriers is more likely. I should note that some gun ranges do not allow FMJ ammunition, so make sure you ask.
This refers to how many feet per second the bullet travels at its fastest velocity, usually at or near the muzzle. Lighter bullets usually have higher velocities.
Stands for jacketed hollow point. Manufacturers designed hollow points to expand in size once within the target. This maximizes tissue damage, blood loss, and shock. This also allows the bullet to remain inside the target, thereby transferring all of its kinetic energy to that target.
Jacketed hollow points or plated hollow points contain a coating of harder metal to increase bullet strength and to prevent fouling the barrel with lead stripped from the bullet.
+P or +P+
Refers to overpressure ammunition. This means that the manufacturer loaded the cartridge with a higher pressure than the standard for the caliber.
This typically produces rounds with higher muzzle velocities. Because of this, +P ammunition is typically found in handgun calibers which might be used for defensive purposes.
Always find out first whether your gun can handle a +P cartridge. Some firearms have injured shooters when the chambers failed to handle the pressure.
Conclusion: Bullet Grains
I hope that we cleared up some of the ammo buying jargon you may run into. Buying ammunition can be a little daunting at first. Do your research before you arrive at the checkout counter, but remember that a well-placed round, no matter what kind, is the right round for the job. The best-suited cartridge in the world does you no good if you miss your shot.
Did you know this information about bullet grains? Do you have any other info? Let us know in the comments section.
Editor’s note: this post was originally published in July 2012. It has been updated and revamped for clarity and accuracy.