Ammunition

Grains do not Refer to Gunpowder?

Gunpowder outside a cartridge

This may seem basic to some of you shooters out there, however the number of calls we get referring to this little misnomer may surprise you. When buying factory ammunition, referring to 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 very small unit of measurement where there are 437.5 grains in an ounce. Therefore, if you were to purchase a box of .223 Brown Bear 55 Grain FMJ, the 55 refers to the mass of the bullet itself, not the entire cartridge—just the projectile.

Gunpowder outside a cartridge
Bullet, Powder, and Cartridge

Some of the confusion comes from the manufacturing and loading of cartridges. Many use grains as a unit of measurement when loading propellants in ammunition, so technically, those who say that 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.

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 what 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 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 that besides using plinking ammunition, try to practice the way you fight. If you spend months becoming a proficient shooter with inexpensive target ammunition, you may find your gun performs differently with self-defense ammunition in play. This is not something you want to learn while trying to defend yourself.

Here is a quick ammunition acronym guide. Most of this information applies to pistol and rifle ammunition, shotgun shells are going to have to wait for another post!

  • FMJ – Stands for 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 depositing 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, where 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.
  • FPS – 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.
  • JHP – 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 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 if your gun can handle a +P cartridge. Some firearms have injured shooters when the chambers failed to handle the blast.

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.

The Mission of Cheaper Than Dirt!'s blog, The Shooter's Log, is to provide information—not opinions—to our customers and the shooting community. We want you, our readers, to be able to make informed decisions. The information provided here does not represent the views of Cheaper Than Dirt!

Comments (30)

  1. I used to own a German 8 mm Mauser and I loaded my own shells. And we counted the grains of powder. The original shells from the military for 170 to 180 grain. I loaded my shelves up to 200 grains of powder. We never referred to the weight of the bullet. This was in 1965 6 7 8 9

  2. I hate to admit it, I always thought grain was gun powder. I guess I should of known it referred to weight because the grain measurement also is commonly used extremely small amounts of gold, silver, etc. usually in coins.

  3. I love to read things and learn. It’s great when you can read stuff from different people of different education levels. That’s what makes this country so great. I would like to thank everyone who responds to articles like this so we all could learn from it.

    1. 16 oz in a pound. 7000 grains in a pound. 7000 grains divided by 16 oz in a pound is 437.5 grains per oz.

  4. Is the powder used in cartridges manufactured in specific shapes to maximize compaction ? Flakes, rounded, or other shapes of individual grains in order to maximize explosive force to deliver the bullet ?

    1. J W: Individual powder [bits] are generally referred to as [kernels] and not as grains, whether they be flake, spherical(round or flattened granules), ball [Winchester-Olin et-al copyright] (granules), extruded(stick, log) and others, if any… Then, again with Black Powder…There’s grams and/or grams equivalent, from the “old days” ad-finitim or, whatever.
      I don’t think the terminological inexactitude will ever be resolved; Not in the near future, anyhow.

      WILL

    2. Will, I think you’re referring to Dram’s equivalent (with a “D” which is given on shotgun loads and it does have to do with comparing it to a black powder load. With black powder, you do use “grains” as a measure of powder, but it’s by weight and not by kernels. I have a duckfoot .36 black powder pistol that uses 12 grains of powder with each load, which I computer s less than one gram. If I did the math correctly, I come up with one gram equal to 15.4 grains. That’s probably not exact, because I started with 2.2 lbs. as equal to one kilogram, and multiplied the 2.2 by 7000 grains per pound, then divided by 1000, but I figure the 2.2 lbs. was probably rounded rather than exact, so I might guess that one gram would be closer to an even 15 grains. Figured I ought to check with a conversion chart online, and it gives one gram as equal to 15.432 grains and one grain is 64.799 miligrams. As for individual powder “kernels”, I wanted to point out there are progressive burning powders that are shaped like a cylinder with a super small hole down the center. When it burns, it burns from the inside out as well as from the outside in. The result is that the surface available to burn increases as the kernel burns, so it produces more gasses, higher pressures, and increased muzzle velocity. A solid kernel has less and less surface area to burn, so the highest presssures created are at the beginning of the process rather than a fraction of a second later.

    3. At Ricochet:
      You are applesolutely correct. But, in all honesty, it was a typo.
      Neuropathy does that to me at times…… and the keys are so close together…I hit the wrong one, and my pinkie and index fingers have minds of their own, and mmmy eyes aren’t as good as they once were….and, and…… But……………! It was the keys’ fault for being too close together, and for them knowing that I’m not a typist in the first place, and I am new to this….and………………
      Am……am……am….I off the hook?
      After 39+ yrs. at the bench…I really should have known better. No More Excuses.
      BTW; The reply about the “kernel” was to point out [that] I have seen and heard ..some people refer to a single *kernel* of powder as a [grain], One person who comes to mind, actually (and honestly) placed–with a pair of red, long pointed tweezers– (7) [flakes] of powder in the pan to bring the weight up to his preferred load of [3.7gr.] for his .38 Spl. WC. I asked him why he did that, and he replied that he had to add those seven [GRAINS] by hand to get the exact weight for each of his loads; At which point, I immediately excused myself… and hastily exited the loading shack door hoping to make it around back before peeing all over myself, but the laughing took over and………I could neither contain nor control myself, stumbling over something on the ground I did not see thru the tears in my eyes.
      This……From one who had been reloading for years before I met him in ’86. This event happened in ’92. SHMG.
      WILL

  5. CTD Rob,

    Thank you for taking the time to write this article. I appreciate accuracy in communication. I love knowing how things work.

    In the spirit of that, I thought I would offer some corrections to your use of the term Mass/Weight and Momentum vs Force..

    In your article you said, “The term grains refers to the projectile’s mass or weight”.

    Technically, weight is the effect of gravity on a mass.

    1) Mass is a measurement of the amount of matter something contains, while Weight is the measurement of the pull of gravity on an object.

    2) Mass is measured by using a balance comparing a known amount of matter to an unknown amount of matter. Weight is measured on a scale.

    3) The Mass of an object doesn’t change when an object’s location changes. Weight, on the other hand does change with location.

    There have been many studies here on earth that show, depending on where you stand on the surface of the earth, that you may weigh a few pounds more or a few pounds less. However, your mass would not have changed. This is caused by fluctuations in the earth’s gravity Cool huh?

    You also mentioned that, “A heavier bullet travels slower but hits with more momentum, while a lighter bullet has a flatter trajectory and greater velocity.”

    Momentum measures the ‘motion content’ of an object, and is based on the product of an object’s mass and velocity. Momentum doubles, for example, when velocity doubles. Similarly, if two objects are moving with the same velocity, one with twice the mass of the other also has twice the momentum.

    Force, on the other hand, is the push or pull that is applied to an object to CHANGE its momentum.

    The collision of one object with momentum into another means that there is an impact force. That is the transfer of energy from one object to another over a period of time.

    This is force.

    So, it the correct term would be “…hits with more force”

    Thanks again for the article!

  6. I was fascinated with your article. Living in so.Ca. you don’t get much of a chance to shoot, unless you travel at least an hour or more to an out door range. So needless to say, I’m a rookie. Please keep up the simple jargon for us rookies. Thank you.

  7. Also a newbie – have 2 Glock 9mm and just gifted myself a Springfield XDS.
    I love learning as much as possible about shooting and gun ownership, in general.
    I like the science behind it all and it’s never a bad thing for a lady to be well informed on the topic 🙂
    Any suggestions for good discussion boards/sites?

  8. I’m a newbie to all of this. Never thought that guns and ammo was so complicated and
    full of technique and science. I enjoy websites like this and stuff on You Tube like
    hickok45,etc. I learn a lot from viewer comments,too.

  9. sorry jacob… for using caps.

    yes the grain amount on the box is bullet wt..,,,, the S is important..

    powder is in small grains.. from ball powder to stick rifle powder..when setting up an automatic loading machine.. you have a powder drum. that has to be set at a certain amoutn of powder..to dump the same each time it indexes on an empty shell… most pistol use flake powder an rifle uses ball or stick.. when setting up the powder drum. you run ten rounds an weigh each powder charge, till you have the spec that ballistic
    gives you for v&p.. to much powder gives you high pressure. an too little gives you blibs. a blib is a bullet lodged in barrel.. dangerous. on both scales… so you adjust the grains of powder..so you get the right velocitie an pressure. on each round..each extra grain of powder can raise pressure..by thousands of psi…sorry i got long winded on the powder grains.

    1. Jim, Good insight. Glad you shared it. So “grain” in the singular refers to the projectile, such as a 55-grain bullet, and “grains” in the plural refers to the powder measurement. I’ve plinked for decades with a variety of guns, and this was still an informative article. For instance, I’d always associated the P+ marking for some reason with wadcutters, but I didn’t realize it actually stood for overpressure ammo.

  10. Jim, I don’t think you read the article very carefully.
    “Some of the confusion comes from the manufacturing and loading of cartridges. Many use grains as a unit of measurement when loading propellants in ammunition, so technically, those who say that grains refer to the propellant are partially correct.”
    He’s saying that you did indeed weigh both powder and bullets by grains. The point of his article was to inform people that when the grain amount is written on the ammo box, it usually means the projectile weight, not the powder.
    –Also, writing in all caps makes you seem less informed on internet etiquette, sorry if I’m being blunt, but it does. No one has perfect grammar, but all caps means you are yelling…google it if you don’t believe me.

  11. YOU ARE MISTAKEN….. GRAINS…REFERS TO THE WT OF THE POWDER… GRAIN IN THE WT OF THE BULLET.

    I WORKED FOR REMINGTON ARMS FOR 30 YEARS.. RUNNING DUPLEX LOADERS RUNNING CENTERFIRE AMMO.. 9MM,,357 ,40S&W
    3030,, 30-06 , 375h&H.. WE WEIGH POWDER BY GRAINS… AN BULLET WT IS GRAIN…

  12. Thank you so much for this article. This subject is one of those things that I wanted to ask about but was afraid to show how much of a newbie I really am.

  13. Good article, would be even better with more discussion of amounts & types of powder in the cartridges.

  14. Thanks for this great info. I’m new to a lot of this and have purchased many guns and ammo already. These kinds of questions are to embarrassing to ask the “know it all” shooters at the range, so much appreciated!

  15. I know your article dealt with modern firearms. But it bears mentioning for the newbie, (also the focus of this article). That SOME cartridges ARE designated in grains of powder. BLACKPOWDER cartridges were designated as .45/75, .38/40, .50/95 et.al. The first numbers being the caliber size and the second being how many grains of BLACK powder they were filled with. It bears mentioning just to avoid confusion for the new shooter, because these calibers are still being made today. Even though most of them are currently filled with a far smaller quantity of smokeless powder.

  16. Ditto Gunner, seemed not only remeadial at first, thinking; Man,I’m out there in traffic merging with these same people, but you’re exactly right,and Rob is right to try and steer the new guys the right direction. No shame in not knowing or understanding,and really since we’re all this gun/shooting/hunting/handloading thing together by a common intrest, so why not ask and learn. Just lettin’ my age show there. My Dad died when I was 14,so at. 24 or so when I decided I wanted to start deer hunting,I bought lots of hunting magazines and a few books,(in the late 70s before the internet)and read and re-read any articles about field dressing a deer so that when I had my first buck on the ground,and no one else was around, I knew what to do without thinking. We all gotta learn somehow,and as remeadial as it seems, Rob is right and thanks to him, maybe some new handloader won’t make the mistake of trying to stuff 110 gr of powder into a .38/357 sized and primed shell.( Don’t believe that’s even possible).Best of luck to anyone who reads and benifits from these posts. Good point Rob,if it helps the newcomer to the sport.

  17. a good article, it may sound a bit over simplified to some of us older shooters, but it’s intended for the newbies, and remember, we were all rookies, full of questions once upon a time.

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