Bullets: Sizes, Calibers, and Types [Guide + Videos]

One of the most daunting things when I first started looking for a gun was…what size bullet to get?

Popular Pistol Calibers
Popular Pistol Calibers

Things got even crazier when I started to look at rifles…

Common Rifle Calibers
Common Rifle Calibers

But don’t worry…we’ll be covering some of the most popular handgun, rifle, and shotgun calibers out there.

As well as the benefits and weaknesses of each.

Then we’ll follow up with some bullet terminology and the different types of bullet tips (hollow point, etc), how shotgun shell sizes work, and a breakdown of the components of a round.

Different Bullet Tips (FMJ, Soft, Open, Ballistic)
Different Bullet Tips (L TO R: FMJ, Soft, Open, Ballistic)

By the end, you’ll be a bullet pro!

Table of Contents

Loading...

Bullet Size & Caliber

First!

For guns, “caliber” means the diameter of the barrel and thus the diameter of the bullet that is going through it.  Usually in inches or mm.

Also for terminology’s sake, “bullet” just means the metal projectile, while the entire thing is called a cartridge.

Parts of a Bullet Cartridge
Parts of a Bullet Cartridge

Here’s some common 9mm bullets.

9mm (115gr vs 124gr vs 147gr)
9mm (115gr vs 124gr vs 147gr)

If you want to jump ahead, check out our suggestion for the Best Place to Buy Ammo Online.

Now what you’ve been waiting for…

Rimfire vs Centerfire

The first differentiator is between rimfire and centerfire cartridges.

The rimfire’s primer is built into the rim while the centerfire cartridge has the primer in the center.  Pro tip…if you can see a circle in the middle…it’s a centerfire cartridge.

Rimfire vs Centerfire Cartridges
Rimfire (First 2 on the Left) vs Centerfire Cartridges

Rimfires are extremely cheap (few cents each) and the .22LR is the most popular rimfire caliber.

.22LR (CCI vs Winchester vs Super Colibri)
.22LR (CCI vs Winchester vs Super Colibri)

This animation shows how the firing pin hits the primer in a cartridge.

Centerfire vs Rimfire Primer
Centerfire vs Rimfire Primer

Here’s some expended casings from a rimfire vs centerfire.

Rimfire vs Centerfire Primer Strike
Rimfire vs Centerfire Primer Strike

For even more differences, see our article on Rimfire Ammo or familiarize yourself with How Guns Work.

Common Bullet Calibers

To make things a little more confusing, there’s a mixture of measurements in inches and millimeters.

There’s also a unit of weight called a “grain” which is used to denote the weight of bullets and gunpowder.  A “grain” is really small since 7000 grains make up one pound.

62gr XM855 vs 77gr SMK vs 55gr FMJ
62gr XM855 vs 77gr SMK vs 55gr FMJ

Now let’s go through some!

More Common Bullet Calibers
More Common Bullet Calibers

.22LR

The “twenty-two” long-rifle is the most common caliber in terms of units sold.

.22LR Round
.22LR Round

It has a bullet weight of around 30-40 grains and is extremely mild shooting in both pistols and rifles.

The recoil is almost non-existent which makes it a great starter round for someone who has never shot a gun or is uncomfortable with the noise.

The low price of the bullets is also great for learning sight pictures.

It is traditionally the starting caliber for shooters.  These things are only a few steps up from a pellet gun round…especially in a rifle (Ruger 10/22) shown below.

They can kill, don’t get me wrong, but they’re mostly for killing rats, snakes, and birds.  They’ll kill an attacker for sure but it might take a shot or six.

For more info:

.380 ACP

Now we’re getting into slightly beefier sizes.

.380 ACP Round
.380 ACP Round

Personally, I would never use a gun with anything smaller than a .380 as my primary carry weapon.

Sometimes called a “9mm Short”, it has seen a major boost in popularity recently thanks to the various “pocket pistols” that have come on the market.

This bullet has relatively low recoil and, at close range, good penetration.

Gun author Massad Ayoob once said of the .380 “Some experts will say it’s barely adequate, and others will say it’s barely inadequate.”  This is a low power round.

Because of the nature of the bullet and the guns that shoot it, it’s going to be relatively useless beyond close-ish range.

For more info:

9mm

9mm Round (115gr)
9mm Round (115gr)

This pistol round is officially known as the “9x19mm Parabellum” or “9mm Luger” to distinguish it from other 9mm rounds, but you will be fine just saying “nine millimeter” or “nine mil” for those in the know.

My personal favorite and if there was a “Goldilocks” round, this would be it.

The very first gun I bought was a 9mm.

They’re fun at the range.  They’re good for defense.

Believe it or not…or actually believe it because it’s true…the 9mm bullet is the same diameter as the bullet used in the .380 and the .38 Special.

The difference between the three is the amount of gunpowder behind it and possibly bullet weight.

9mm (115gr vs 124gr vs 147gr)
9mm (115gr vs 124gr vs 147gr)

It is the standard round for NATO countries and the majority of police forces around the world.

It is mild shooting, can vary in weight from 115-147 grains, and has varying stopping power based on the type of bullet (hint, go with hollow points).

Ballistics Gel Testing
Ballistics Gel Testing

Many, many guns use this size as well.  A compact 9mm gun can be used for concealed carry.  Most of the guns that use this size can hold on average 15-17 rounds in the magazine.

9mm 147 Federal Hydrashok HST
9mm 147 Federal Hydrashok HST, Our Favorite Self-Defense Round

And now…there’s been a huge rise in popularity of Pistol Caliber Carbines (or PCC).  Get the nice ergonomics of a rifle but with the price and hollowpoints of the 9mm.

For more info:

.40 S&W

.40 S&W Round
.40 S&W Round

Remember how I said the 9mm was the “Goldilocks Round”?  If that’s the case then the .40 is her big, angry, whiskey drinking sister.

Originally designed for the FBI as a reduced 10mm cartridge and popular with other law enforcement agencies ever since.  More kick when compared to the other popular handgun cartridge, the 9mm.  Weights of the bullet can vary from 155 to 165 and 180 gr.

Note that the FBI recently decided to move back to the 9mm since agents are able to shoot more quickly and more accurately with 9mm compared to the .40 S&W.

For more info:

.45 ACP

.45 ACP (230gr)
.45 ACP (230gr)

Designed in 1904 by Mr. John Browning himself for the famous 1911 pistol, this round has one heck of a history.

Rock Island Armory 1911 GI Midsize
Rock Island Armory 1911 GI Midsize

This thing is a big bullet with stopping power to spare.

The choice of many police officers and military personnel for years, the .45 caliber round has proven itself time and time again.  I could probably do an entire article on just this bullet.

It has a large bullet of around 230 grains and has moderate recoil.

9mm vs .45 ACP
9mm vs .45 ACP

I can tell you from personal experience that this is not a round to hand to someone who’s never fired a gun before.  Its stopping power is renowned and has a nostalgic following.

For more info:

.38 Special & .357 Magnum

The “thirty-eight special” is most commonly found in revolvers.

.38 Special Round
.38 Special Round

It has manageable recoil but is still quite a handful when in a very light/small revolver.  It has a longer cartridge and more powder in said cartridge but it is a slower, heavier bullet than the 9mm.

The FBI used this cartridge as its standard issue for a very long time.

The .357 Magnum is identical to the round except for being slightly longer.

.38 Special vs .357 Magnum
.38 Special vs .357 Magnum

You can safely fire a .38 Special in a .357 Magnum gun, but don’t try the other way around due to size and pressure constraints.

Bullet weights vary from 110 to 132 to 158 gr.

.357 mag ammo is pretty
.38 and .357 in the S&W 686+

For more info:

7.62x39mm

The Soviet round used in the AK-47 line of rifles.

7.62x39mm
7.62x39mm

It has moderate recoil, great knockdown power, and a bullet weight of usually 123 grains.

There is a high availability of military surplus ammo which makes the round very affordable.  Plus check out its bullet size vs the 5.56 coming up next…

5.56 vs 7.62x39mm
5.56 vs 7.62x39mm

For more info:

.223 / 5.56x45mm

5.56 Round
5.56 Round

The “two-two-three” (inch) Remington has almost the exact dimensions as the “five-five-six” (mm) NATO cartridge.

The 5.56 has higher pressures than the .223, so .223 rounds can be fired in a 5.56 rifle, while 5.56 rounds should not be fired in a .223 rifle.

Deconstructed 5.56 XM855 Round
Deconstructed 5.56 XM855 Round

Bullets are around 55 grains and the cartridge has light recoil.

Assorted 5.56 Rounds (XM193, XM855, Gold Medal 69gr)
Assorted 5.56 Rounds (XM193, XM855, Gold Medal 69gr)

It is the ammunition used in the M16/M4/AR-15 line of rifles and there’s still endless debate on its effectiveness in combat.

For more info:

.308 / 7.62x51mm

The “three-oh-eight” (inch) Winchester is almost the same dimensions as the “seven-six-two” (mm) NATO round.

7.62x51mm
7.62x51mm

There are special considerations when mixing the rounds but unless you know what you are doing, stick with the round intended for your rifle.

It is a popular hunting round with moderate recoil, high stopping power, and a wide range of bullets available from 150 to 208 grains.

Plus…one of the most popular heavier caliber machine gun and sniper rounds for many militaries around the world.

Assorted 7.62x51mm (MEN 147gr, PPU 165gr, PPU 180gr, Gold Medal 168gr
Assorted 7.62x51mm (MEN 147gr, PPU 165gr, PPU 180gr, Gold Medal 168gr

For more info:

.50 BMG

Not really common for civilians, but I just had to have it in here.

.50 BMG
.50 BMG

It’s huge and has huge recoil with awesome range (confirmed kills at 2000m+), and you definitely don’t want to be on the receiving end of the bullet.  660 grains of pure stopping power.

Common Calibers in Room
Common Calibers in Room

This Barrett was OK because I was standing and it had a suppressor!

Still with me?

Common Bullet Types & Terminology

Full Metal Jacket (FMJ)

This is the most common type of bullet and consists of a soft metal core, such as lead fully encapsulated by a harder metal, such as copper.

FMJ vs Hollowpoints (9mm and .45 ACP)
FMJ vs Hollowpoints (9mm and .45 ACP)

They are usually pointy, round, or even flat.  Wound channels are typically small and go through a target.

Great for the range but not preferred for defensive rounds.

Hollow Point (HP)

Hollow points are made to expand once they hit something.  They are the go-to round for police officers, concealed weapon carriers, and home defense guns because of their stopping power.

9mm 147 Federal Hydrashok HST
9mm 147 Federal Hydrashok HST

Open Tip (OTM)

Open-tip bullets look like hollow points since they have an opening at the top, but this is more because of their manufacturing process.  The openings are too small to expand effectively.

Different Bullet Tips (FMJ, Soft, Open, Ballistic)
Different Bullet Tips (L TO R: FMJ, Soft, Open, Ballistic)

Regular FMJ’s are created from small copper cups where the bottom of the cup becomes the tip of the bullet.  Open-tip bullets are the opposite, with the bottom of the cup becoming the bottom of the bullet.

Open-tip bullets are sometimes also known as Open Tip Match (OTM) since they are preferred by long-distance shooters.  The manufacturing process for open tip bullets creates a more consistent round than FMJ.  Important when you’re shooting hundreds of yards!

Ballistic Tip

This is what you get when you combine the aerodynamics of an FMJ with the stopping power of a hollow point.  This is a hollow point covered with (usually red) plastic to mimic the profile of an FMJ.

They are mostly used in hunting or precision shooting.

Assorted 6.5 Creedmoor (L to R: Federal FMJ, Soft 129gr, Ballistic Tip 120gr, Gold Medal 140gr)
Assorted 6.5 Creedmoor (L to R: Federal FMJ, Soft 129gr, Ballistic Tip 120gr, Gold Medal 140gr)

Below you’ll see that the bottoms of the bullets are more streamlined.  This design is called “boat tail” and produces less drag as the bullet flies through the air.  HPBT is short for “hollow point boat tail.”

.308 (168gr vs 208gr)
.308 (168gr vs 208gr) Boat Tail Bullets

Soft Point

This is an earlier attempt to get the ballistic advantages of an FMJ with better expansion.

Assorted 7.62x39 (FMJ, Open, Soft, FMJ)
Assorted 7.62×39 (FMJ, Open, Soft, FMJ)

In soft point bullets, part of the lead is exposed at the tip.  The softer lead is designed to flatten better when the bullet hits a target.  But for the most part, ballistic tips have surpassed the performance of soft points.

Shotguns

The most popular sized shotgun round is the 12 gauge.

Types of 12ga Shotgun Shells (L to R: Bird, Buck, Slug)
Types of 12ga Shotgun Shells (L to R: Bird, Buck, Slug)

Recoil can vary from moderate to high based on round.

Shotgun ammunition is the most versatile with three main types of loads.

12ga Shotgun Shells, Opened (L to R: Bird, Buck, Slug)
12ga Shotgun Shells, Opened (L to R: Bird, Buck, Slug)

Bird Shot

Shot Size Chart, Shotgunworld
Shot Size Chart, Shotgunworld

Birdshot consists of the top row and is pretty small pellets numbering in the dozens in each shell.

12ga Birdshot, Opened
12ga Birdshot, Opened

Great for hunting birds and blasting clay pigeons, but not the best for home defense.

Ok recoil.

Buck Shot

The overall best home defense round is buckshot.  00 (“double-aught”) is the go-to load.

12ga 00 Buckshot, Opened
12ga 00 Buckshot, Opened

It’s 9 solid lead balls the same diameter as the 9mm handgun bullet.

Much more recoil usually…but you can also find reduced-recoil buckshot rounds too.

Slugs

Slugs are single projectiles that are around 1 oz of solid metal that really bring the hurt.

12ga Slug, Opened
12ga Slug, Opened

However, they don’t have the spread of birdshot or buckshot.  But, in the hands of a solid shooter, they can be accurate up to 100 yards.

12ga Slugs
12ga Slugs

For more info:

Components of Common Cartridges

What makes up a cartridge?

Here are just a couple breakdowns of super popular calibers.  You can see the difference in powders & bullets for each type.

Deconstructed 9mm Round
Deconstructed 9mm Round
Deconstructed 5.56 XM855 Round
Deconstructed 5.56 XM855 Round
Deconstructed 7.62x51 Round
Deconstructed 7.62×51 Round

Conclusion

There you have it…now you’re a bullet pro!

Continue on with a deeper dive into Popular Handgun Calibers and Popular Rifle Calibers…or head on over to see where to buy some Ammo Online.

And if an expertly created beginner handgun course is what you’re looking for…check out Gun Noob to Gun Slinger.

170 Leave a Reply

  • dan stewart

    Is the 6.1x6 the same as a 9mm thanks Dan.

    1 second ago
  • Rudy

    Maybe also adding the .30-30

    2 days ago
  • Rudy

    Very nice article, I enjoyed it. An overview with dimensions would be nice to.

    2 days ago
  • Smith

    .223 is a larger caliber than 5.56, yet your article states .223 can fire into a 5.56?

    4 days ago
    • David, PPT Editor

      .223 cal Remington and 5.56mm NATO use the same .224" bullets. 5.56 NATO chambers are able to handle higher pressure and are safe for both .223 Remington and 5.56 NATO cartridges.

      4 days ago
  • Bob Peterson

    Excellent article! Well written Agnes easy to follow.

    1 week ago
  • Yedi Yedwabnick

    what kind of ammo do I need for a Ruger 22 caliber pistol for self defense

    3 weeks ago
    • Vladatmail

      You need to buy .750 nitro

      1 week ago
      • Vladatmail

        Sorry .700 nitro

        1 week ago
  • John

    Awesome! Thanks

    1 month ago
  • Stevepski

    Very clear and informative. Question: 44 caliber? No mention of this particular round. How does it compare to a 45 caliber?

    2 months ago
    • David, PPT Editor

      .44 Cal comes in two main flavors, .44 Magnum and .44 Special. The .44 Spl is basically just the .44 Mag but downsized a bit. .44 Mag is a good deal more powerful than .45 ACP, but it has a rimmed cartridge so it is almost only used in lever-action rifles and revolvers. The .44 Spl is almost the same power as .45 ACP, but again has the rimmed cartridge. .44 Magnum is a great choice for a lever-action rifle or for a bear-defense revolver! But as a CCW, plinker, or HD gun it is a bit on the heavy and overkill side of things.

      2 months ago
  • BRENDA KENNEY

    WHERE DOES A .32 CALIBER PISTOL RATE WITH THE OTHER AMMO YOU WENT OVER?

    2 months ago
    • Walt Ilczyn

      The 32 acp is being resurrected by Walther some time later this year. It will be the PPK/S model similar in performance that James Bond made famous in his movies. The 32 acp is making a comeback like the Beretta 3032 and Kal-tek P32.

      1 month ago
    • BRENDA K.

      WHAT ABOUT A 30/30?

      2 months ago
  • Eddie Taylor

    Great article. Great job! One of the better descriptions I have seen on this subject.

    2 months ago
    • Eric Hung

      Thanks, Eddie!!

      2 months ago
  • RON DRAKE SR

    WHAT HAPPEN TO THE 45/70 AND THE 30/30

    3 months ago
  • Imhotep Shom'er

    I'm a firearms instructor, and have been for a number of disciplines, agencies, and years. Your article on bullet sizes, calibers and types has been the very best I've ever seen. It was very comprehensive and "gun noobish" and I am looking forward to reading your other works, great job!

    3 months ago
  • Kyle deveau

    Hi, I’m actually doing a research paper that includes minie balls: a new and revolutionary invention that was used during the civil war. Any connection I can use to support that through we evolve in our machinery?

    5 months ago
    • Kyle deveau

      “Through *war* we evolve in our machinery?”

      5 months ago
      • David, PPT Editor

        I don't know of any connection Minie balls had with other machinery or technology, but war and researching for weapons have resulted in loads of other unrelated advancements. Minor things like duct tape all the way to world-changing technology like Penicillin and canned food.

        5 months ago
  • WTKJD

    The first graphic is better captioned as “Common Cartridge Sizes.” A bullet is a component. There is virtually no difference in size between 9mm Parabellum, .38 Special and .357 Magnum bullets, but a big difference in cartridge size between them. While the media conflates “cartridges” with “ bullets,” gun experts don’t.

    5 months ago
  • Gale

    Is 30 carbine same as 30/30 round?

    5 months ago
    • David, PPT Editor

      No, .30-30 Winchester was developed in 1895 and is most commonly seen in lever-action rifles. .30 Carbine was developed in the 1940s and is most commonly seen in the M1 Carbine

      5 months ago
  • Daha

    Thanks a bunch ,now I understand better these terminologies

    6 months ago
  • Richard Venneman

    Why no mention of the 357sig?

    7 months ago
    • Mark

      Yeah, I was wondering that too... or did it join the 10mm category of obscure calibers.

      5 months ago
  • Matt

    Loved the article as a noobie to the sport always looking for new informative articles to read. This was a good one. Thanks Matt

    8 months ago
  • Jay

    First things first,purpose of round.25 acp was designed for the baby browning,which I can palm completely in my boney hands and when you walked past a nazi officer you could feign a heil Hitler and pop a round into his forehead from mere inches away and keep walking. QUITE FATAL and preferred tool of French underground resistance for sneaky assassinations not combat. Yes a bazooka has more stopping power than a Daisy Red Rider.

    10 months ago
    • crackerboy

      Re: .25 ACP v. .22 LR The article gives the impression that the two calibers are more or less comparable for self-defense. Not accurate. The "stopping power" (annoyance potential?) is comparable only in 2 - 3" barrels, and even then not in all loadings. For example, the .25 ACP out of a 3" barrel generates only about 100 lb/ft maximum energy. The .22 LR, depending on the load, will produce to up to 120 lb/ft. Furthermore, it's available in lead hollow point which MIGHT expand some at handgun velocities, whereas the .25 is fully-jacketed. Someone once made a hollow point .25, but they wouldn't expand in wet phone books out of my Baby Browning clone. Add in the greater tendency of .25 pistols to malfunction due to a variety of causes, such as improper grip, dirt and garbage, failure to feed, etc. and the choice is pretty clear. Some .22 pistols are less than reliable, but the caliber is available in revolvers. Malfunctions are generally due to ammo quality in .22's, and with a wheel gun you just pull the trigger again. Above 3" of barrel, the comparison becomes absurd.

      6 months ago
  • Rollo N Rendleman

    I have purchased my first gun, Sig Sauer P250 40 S&W . What is the best and cheapest round for the range? Also, I know for home defense is a hollow point, but does the grain weight matter at extreme close range?

    10 months ago
  • Chase P

    This is a great article. Like always very detailed and accurate. Thank you for the information!

    11 months ago
    • John

      You bet! Thanks for reading, Chase!

      11 months ago
  • crypto7

    If I could attach the PDF I have of the 2015 FOIA request for the FBI's 9mm justification I would, but they make a very strong case that "stopping power is a myth" and when you're talking about neutralizing an attacker you're talking about 1) shot placement, and 2) the projectile. Actually, it's here: http://looserounds.com/2015/11/09/fbi-9mm-justification-foia/ but you have to zoom the JPEGs to read them....

    1 year ago
  • drojo

    Should be capitalized as: Five-seveN (get it?)

    1 year ago
  • John Magee

    Eric, wonderful site but it’s not a bullet cartridge it’s just a cartridge.

    1 year ago
    • DrFunkenstein

      The cartridge holds a bullet so I don't think Eric's wrong calling it a bullet cartridge, nor do I think you're wrong simply calling it a cartridge. Tomato/tomahto....

      1 year ago
      • crypto7

        You misspelled tomahto. ;-)

        1 year ago
        • Jay

          Toematta

          10 months ago
  • Rebel

    Good article,but you overlooked 3 rounds that are very common.The 22 magnum ,44 spcl,and 44 magnum.

    1 year ago
  • Farhan

    All i can say is "AMAZING" Thank U...

    1 year ago
  • mike

    E=M*V squared. Nice to see bullet descriptions nd masses. I would like a similar article about velocities (and energy) of the various rounds.

    1 year ago
  • Russell

    I have no experience with guns and very much appreciate the excellent information you've given on your site. I would never have understood any of this, though I have heard many of the terms used. Question: I have a friend who re-loads bullets in his home in his spare time. Is this a safe thing to do with toddlers in the house?

    1 year ago
    • Rob W

      Absolutely safe, At least, as safe as anything else. You have far more dangerous stuff under the kitchen sink. As long as you think safe and practice safety it is more safe than bleach or laundry packets.

      1 year ago
    • Matthew Collins

      Hey Russell, as long as the materials are stored safely and your friend knows what he's doing, it's no more dangerous than anything else.

      1 year ago
      • Russell

        Thanks - I do think he is well informed. Was just worried. Appreciate the info.

        1 year ago
  • jason

    Not one mention of .32 acp? I know its a controversial defense round and there aren't many gun options on the market but it's more manageable for smaller or weaker shooters than 380 in a pocket gun and that's very important to consider.

    1 year ago
    • Matthew Collins

      Hey Jason, unfortunately if we included every caliber, this list would be too long. .32 acp is a good round, but it's just not common enough, either on store shelves, or as a chambering for new guns. We do have a couple articles on guns for shooters with less hand strength, and disabled shooters and .32 acp and .25 acp both make the list there, for the reasons you've mentioned. Thanks for bringing this up and reminding folks of some of the other options that are out there!

      1 year ago
  • 22 Cal. Ammo Info – Hunt Sodak

    […] Basic Bullet Guide: Sizes, Calibers, and Types – Pew Pew Tactical – Jan 31, 2016. The rimfire's primer is built into the rim while the centerfire cartridge has the primer in the center. Rimfires are extremely cheap (few cents each) and the. 22LR is the most popular rimfire caliber. For even more differences, see our article on rimfire ammo or familiarize yourself with how guns work. Centerfire. […]

    1 year ago
  • Caitlin

    Can you help clarify the difference between the .50AE and S&W 500 magnum bullet?

    1 year ago
    • Rob W.

      The .50 BMG (Browning Machine Gun) and the Smith and Wesson pistol 500 should say it. The .50 BMG was used in WWII up to today and is impossible to hide in your hand. It is capable of taking down military aircraft, piercing the armor of some personnel carriers, and was used commonly in the wing guns of aircraft for air to air combat. The .500 Smith and Wesson handgun round is relatively new, can be hidden in a mans hand, and is for pistols.

      1 year ago
    • kark

      500sw is bigger. search the dimensions up

      1 year ago
  • Denz

    Simply to my understanding, Each caliber size depends mainly on its diameter . try not to get confused on the 2 system .of measurement ,. once you figure it out you would no longer be confused on how they arrived in sizing...the bullet.. Sometimes there are bullet sized which is almost of the same diameter.like 9mm caliber bullet and the , .357 bullet..In here id like to know what differs them in terms of power?Was it the amount of powder grain or does it have something to do with the whole ammo total length.

    1 year ago
    • Rob W.

      Allow me to say this. There is no rhyme nor reason related to a standardization of bullet or gun identities. Due to SAMMI standards and military there are some standardization, certainly. But there is NO common denominator to be found as far as names. go. For example, I have a .380 Bersa Thunder and a .38 Smith and Wesson Combat Masterpiece, and a .38/.357 S&W double action and a .38/357 Uberti Single action. The .380 and the 9mm are the same diameter but not the same as the .38. No, the .38 and the .357 Magnum are the same size, except the case is longer in the .357 Magnum. Now, there is a difference between the 9mm Parabellum and the 9mm Makarov in that one is 9mmx19mm and the other is 9mmx18mm and they will not shoot in the same guns. If you want that you need a .38/357 but don't try to shoot a .357 magnum in the .38 Smith and Wesson because you can't. It won't fit. But the .38 will fit and shoot in the .357 Magunm, both in the Double action and the Single action. Make sense?

      1 year ago
    • Eric Hung

      The powder will vary a lot based on type of powder, the total cartridge length (how deep set the bullet is), and other factors.

      1 year ago
  • JDK

    I would not go so far as to suggest all 9mm projectiles are interchangeable between .380, and 9x18, .38SPL, and 9x19 cartridges..

    1 year ago
    • Eric Hung

      True!

      1 year ago
  • Roger L

    CAN I TAKE A 9MM HANDGUN INTO CANADA WITHOUT ANY PROBLEMS GETTING ACROSS THE BORDER? PLANNING AN ALASKA TRIP AND WANT SOMETHING FOR PROTECTION.

    1 year ago
    • .50 BMG GUY

      If you're going to Alaska Rodger then you will definitely need more stopping power than a 9mm ! If you are planning to use a handgun ad your only weapon I would suggest th S&W 500 or a Dessert Eagle 50 cal. For an semi automatic . If you are going to use a rifle you would do well to have a 300-338 win mag or 7mm Remington Magnum . These three calibers will handle anything in North America . Good luck on your trip and with getting any of these through the border without problems . You would probably be better off just shippng your weapon of choice to the address in Alaska that you are going to before you leave . That way it will be there when you arrive or shortly after you do . Or you may even considered getting what you want once in Alaska . That will definitely be the safest way of getting what you need without problems . I hope my advice helps .

      1 year ago
    • Eric Hung

      YOU'LL HAVE TO CHECK WITH THE PROPER AUTHORITIES.

      1 year ago
  • Erik

    Thanks! Clear, simple and concise. ( Humorous too)! Perfect

    1 year ago
    • Eric Hung

      You're so welcome, Erik!!

      1 year ago
  • Rodney

    bravo, finally a quick reference guide to go in my saved file. Thank you so much.

    1 year ago
    • Eric Hung

      You're so welcome, Rodney!

      1 year ago
  • Jack

    Thank you Eric for the helpful information. I got started is shooting at 70 years young.,5 years ago, i enjoy indoor target shooting and have taken many lessions. So much to learn but very enjoyable sport. You cleared up a lot of questions i had , thank you for the professional information. jack

    1 year ago
  • Curious

    Hello, what does an (F) stand for on a .22

    1 year ago
    • harvey

      .22 rimfire

      1 year ago
  • Byron

    I am going to buy a gun and appreciate this info. Thanks.

    1 year ago
  • Gah8\'s

    I am glad that someone took the time & talent to get this caliber cataloging done. I consider myself versed in firearms and ammo of the common variety, and Mil-Spec too. But, yes the big 'but' of this issue as it applies to me and my knowledge of ammo. Talking ammo is my weakest test in good gun talk with fellow like minded individuals and such. This information is thankfully taking some of us a tad higher in the 'Gun IQ' part of our thoughts and conversations. I thank the author and I am glad I read it.

    1 year ago
    • Eric Hung

      Glad we could help you out!

      1 year ago
  • Thomas F. F. Joyce

    Great data thanks

    1 year ago
  • Thomas F. F. Joyce

    Great data, I try to remember this stuff but I need reminders like this

    1 year ago
  • frank

    Well done. Great analysis and easy to read. Thanks

    2 years ago
    • Eric Hung

      You're so welcome, Frank!

      1 year ago
  • Frank

    no 7mm rem mag

    2 years ago
  • Tobin Thomas

    Hi, Eric Hung thanks for the information. Great article easy to read.

    2 years ago
    • Eric Hung

      You're welcome, Tobin!

      2 years ago
  • Robert Woznicki

    How did Harry Potter get of the hill? By flying. (J.K. Rolling)

    2 years ago
  • Robert Woznicki

    J.K.

    2 years ago
  • Robert Woznicki

    I'm gonna be a Jean-ass.

    2 years ago
  • RBQ

    I am a bit confused about the actual dimensions of the .380 & the 9mm "short" cartridges. Are they the exact same size? If so, why do manufacturers continue to use both designations? That being said, can the .380 & the 9mm "short" be fired in a standard 9mm? I have a FEG RK 59 9mm. It was sold to me as a .380, but, on inspection, I saw the 9mm stamping on the slide. I think the previous owner had been using .380 ammo in this pistol. Could this have caused some kind of damage? Great article.

    2 years ago
    • Eric Hung

      Hey RBQ, acccording to Wikipedia, "9mm short" is the same as .380. But I would double-check your gun with someone more knowledgeable because you don't want to shoot the wrong round and also to look at possible damage.

      2 years ago
  • Minguad

    This is great! I'm a writer and I hadn't been able to find anything online with easy to understand information until I found this. Thank you so much!

    2 years ago
    • Eric Hung

      You're so welcome!

      2 years ago
      • Simon

        Eric why would ya need a 50 bmg, when like, something like a 45 would kill just as well?

        2 years ago
        • Andrew Whitehill

          Because, why wouldn't you want overwhelming devastation and the ability to hit whatever your target when it is behind a tree and a car, wearing a bullet proof vest. It's kinda like having a mile of targeting time. That's a long way to run and get tired before it kills you.

          2 years ago
  • DesiBanda

    Great Site! very Clean and interesting. Keep up the good work.

    2 years ago
    • Eric Hung

      Thanks so much!

      2 years ago
  • Scotty

    Nicely done boss, it's a rarity to find an article with little bias while maintaining the informative concept. Appreciate the few things I learned, thank you... Keep up the good work!

    2 years ago
    • Eric Hung

      You're welcome Scotty!

      2 years ago
  • Andrew Smart

    Well hell, I'll just go ahead and echo what a lot of others are saying: thanks dude; extremely accessible and precisely the information I was desirous of. Go you!

    2 years ago
    • Eric Hung

      Thanks Andrew!

      2 years ago
  • Curt

    Okay, I'll be first to admit that .45 ACP or 9mm Parabellum is better than a .22 Magnum or .22 LR. Often I carry a .22. Why? First, I try to stay away from anywhere there might be a problem. That means I avoid certain neighborhoods and avoid places at certain hours. Life is much easier if I'm not in a situation where I need a gun. Second, if I don't have a good shot at a bad guy, I'm not going to shoot. With a .22 I'm pretty much limited to close range head and throat and liver shots if I expect anything more than an angry response that will hurt me. Personally, I hope I never have to shoot anyone. Thirdly, and the main reason for such a small caliber, is that it fits comfortably under anything and while it is very limited, it can stop a bad guy. In winter, I usually carry .45 or 9mm.

    2 years ago
    • Curt

      You should probably carry the gun that delivers the most momentum to your target considering the clothing you're wearing and laws of your region. I've been shooting guns for over 45 years, so I'm not too concerned that even while dodging and moving that I won't hit my target, so I'm not overly concerned with a too small caliber. Your best defense is to avoid [laces that might be trouble and if trouble still finds you, talk your way out of whatever it is.

      2 years ago
  • Vimbai

    Great article Eric. Well prepared.

    2 years ago
    • Eric Hung

      Thanks Vimbai!

      2 years ago
  • David

    Great info!

    2 years ago
  • Jerry Henderson

    I don't know what the "caliper method" is, but you've addressed my concerns. Thank you!

    2 years ago
  • Jerry

    Great article, but I've got a question: I purchased a 9MM bore sighter to "zero-in" my .380 ACP ($7.50 for the 9MM vs. $25-$30 for a .380). The laser will fit into the barrel, but not far, so the slide will only close about halfway. Is that still far enough to accurately adjust the sights?

    2 years ago
    • Eric Hung

      Hey Jerry, I believe the 9mm is slightly less diameter than the .380 so there will be some play there. As far as how deep it goes in...more is probably better but it should be enough. I've always gone with the caliper way of making sure the sights are aligned.

      2 years ago
  • Dep

    Great article. Couple of corrections? the 9mm is not the same size bullet as the .380 or the .38 special. It's actually about .36 caliber. Slightly smaller and the .30 Caliber carbine was used way past Korea, up to the late mid-60's in the Vietnam war.

    2 years ago
  • Dick Baker

    Great Article! Question: Why does Winchester name its .22LR ammo: M-22? What is the definition of "M"? Thanks,

    2 years ago
    • Eric Hung

      My guess is it's just a naming convention. They are marketing the M-22 ammo more towards rimfire AR rifles so they might have added the M for some M4/M16 association. Just guessing.

      2 years ago
  • Sam Armstrong

    What do you think of the 17cal.?

    2 years ago
  • Arrie

    Hi Eric, This might be a bit specific, but do you know if the cartridge case wall thickness may vary for the same calibre? I've read that cartridge casings occasionally are made out of different materials, wouldn't that require different dimensions?

    2 years ago
    • Eric Hung

      It does based on manufacturer. Sometimes reloaders will segment their brass based on manufacturer since it makes enough of a difference. You'll see brass, nickel plated brass, steel, etc. Not sure if those would require different dimensions.

      2 years ago
  • Debbie Brown

    This is the most informative article I have read about ammunition. Complete, concise and easy to follow! I teach firearms training to civilians, law enforcement and security officers, and covering ammunition has always been a task because of all the variations of ammo. Thanks for making it easier to explain.

    2 years ago
    • Eric Hung

      You're so welcome Debbie!

      2 years ago
    • Matthew Collins

      Awesome, thanks so much for the kind words, and glad we could help!

      2 years ago
  • Robert Hall

    Hi Eric, a little background I am retired cop and started out with a 38 revolver went 2 in 9 and then to a 40 Auto. Now there is talk that the department is going back to a 9 as a result of studies stating there is less recoil on the nine as well as lighter in weight smaller in size and less expensive to shoot. What are your thoughts? Thanks in advance for your response I respect your opinion.

    2 years ago
    • Eric Hung

      Hi Robert, I love my 9's for those reasons you mentioned. Also the new tech in 9 hollow points make them pretty effective.

      2 years ago
      • Darr247

        According to the state trooper that taught part of a required carry class I attended, the main reason they switched to 9mm was they want to have as many shots as possible available without changing magazines, and the same size 9mm magazine holds more rounds than .40S&W and LOTS more rounds than a .45ACP.

        2 years ago
  • Giovanni Socci

    Great article,I wished you had included the .338 Lapua and the .338 Winchester, but perhaps that s beyond your readers curiousity,still a great article.thumbs up.

    2 years ago
  • Charles

    I am just really surprised to not see the .270 win on the list. It is a great all around round that is more common then some listed. With thay said I did like the article and did get some info out of it.

    2 years ago
  • Carl Pernel

    Hi. Great article. But I still have a question you may be able to answer for me. Some years ago my late dad owned a Smith and Wesson that had been made in Spain in the 1930's. It was a five shot revolver, break open, and we thought it was a .38. We took it to the police in the days when they still used .38's and the cop took a cartridge from his speed loader. It slid into one cylinder in the gun, but the length of the cartridge made it impossible to close the gun. So what calibre could this Spanish made S & W revolver be? The cylinder takes the width of a .38 cartridge but not the length. Any ideas on what caliber of bullet this antique Smith and Wesson made in Spain in the 1930's might actually use?

    2 years ago
    • Eric Hung

      Hey Carl, I'm not sure...not the best authority on foreign revolvers. You might try your local gun shop or post up some pics on forums.

      2 years ago
  • Donna

    Very helpful article. My husband has many guns and has used guns for about 45 yrs. Now I finally feel I understand some of what he talks about. I am just beginning to shoot. I pulled up multiple articles to try to educate myself a little more and this was the only one I could read start to finish because it made sense. Thank you.

    2 years ago
    • Eric Hung

      You're welcome Donna!

      2 years ago
  • Scott Schoenfelder

    What do you think of the new 22 TCM? I have both a 1911 pistol and rifle chambered for this rd.

    2 years ago
    • Eric Hung

      That's new to me! How does it shoot for you?

      2 years ago
      • Scott Schoenfelder

        It shoots great out of my RIA 1911 with 5in barrel, sometimes you get a fireball. The velocity is about 2100 -2400 FPS but hardly any recoil. Out of the rifle the FPS goes up to 2700 FPS, you can tell it has some power but still not much recoil when you pull the trigger. You need to check it out on the RIA website. They even make a conversion kit for a Glock 9mm to convert it to the new cartridge.

        2 years ago
        • Eric Hung

          Awesome, thanks for that Scott.

          2 years ago
  • Jay

    Great article. Easy to read for a novice and easy to understand, I really appreciate it.

    2 years ago
    • Eric Hung

      Thanks Jay!

      2 years ago
  • carl

    Eric what is the difference between 223 and the 5.56x39 and if I can witch one for the other I have two old arisaka and I need to know what caliber they are can you help me

    2 years ago
    • Eric Hung

      Hey Carl, the .223 is close to the 5.56x45. I'm not familiar with a 5.56x39...do you mean 5.45x39 which is the standard round for the AK-74. I'm also not familiar with arisaka's so you might have better luck in a forum or bringing it to a smith. You don't want to put the wrong caliber in a gun.

      2 years ago
  • Sid

    Just starting out learning about guns. all the ammo stuff was slightly confusing, but your articles totally cleared it up. Thank you very much.

    2 years ago
    • Eric Hung

      Thanks Sid!

      2 years ago
  • Max Hamilton

    Hi Eric, It is great info, very useful article, many thanks.

    2 years ago
  • krshh

    It's a very useful article and I request u to tell some something about different guns and their powers

    2 years ago
  • john

    Total newbie. Great article... In terms of defense, what round type or classification would be best for close quarters (townhouse) with less wall penetration? Frangible?

    2 years ago
    • Eric Hung

      Hey John, yup! I have caliber specific ammo recommendations on the site so check them out. Use the contact us page if you're having trouble finding it.

      2 years ago
  • Alex

    Well written article, enjoyed reading it. I also found this ammo guild on 45 ACP informative.

    2 years ago
    • Eric Hung

      Thanks Alex!

      2 years ago
  • Richey Stewart

    Are you taking pictures with a cellphone? Whatever you are doing the pictures of your bullets are distorted. They do not give accurate depiction of their actual size of calibers listed. They are elongated and thinly proportioned. i know the difference in most shells but there are alot of people that will be greatly surprised at the true size of lets say .357 or 45 long colt as opposed to .45 acp. Your picture of a .50 caliber bullet makes it look no bigger than a 30-06. there is a huge difference you can not see in your so called photos.

    2 years ago
    • ehung

      Hi Richey, thanks for your comment. I do admit I'm not the best photographer but I tried to not use a potato camera. Hopefully the quarter in the pictures gives some sense of scale.

      2 years ago
  • Christina Schmitz

    I have a Thompson Center Encore .243. The .243 is not covered in your bullet size calibers guide. Can you tell me your take on this caliber? Thank you.

    2 years ago
    • ehung

      Hi Christina, I'd love to but I don't have any current experience on it yet!

      2 years ago
  • Darren Justice

    $1 for slugs a piece? More like up to $5 a piece

    2 years ago
    • ehung

      Those are some fancy slugs then!

      2 years ago
  • John

    Great information, enjoyed article very much. What are your thoughts on the 7mm Mag vs 308 cal ?

    2 years ago
    • Joe

      The 7mm Rem Mag is a much faster, flatter shooting round. It is a .284 bullet diameter that is usually 150-175 gr. The 308 Win is a .300 bullet in a non-magnum case. It shoots slower and has a more parabolic trajectory. Typically the bullets are also around 150-175 gr.. I shoot long range (500-750yds) and elk with my 7mm, I shoot shorter ranges (100-500yds) and deer with my 308. Which is better? They are different and both very good at what they do. They are kind of an apples/oranges comparison. I would suggest of the two, the 308 is a better all around caliber; especially for a beginner. The 7mm has far more recoil, and is better compared to a 300 Win Mag.

      2 years ago
  • rick

    I was in the navy.Our guns shot 5in 54 rds.What is the decimal for a 5in 54compared to a 38rd.

    3 years ago
    • George

      A 5 inch (127 mm) would be 5.00 caliber. The 54 refers to the barrel length (54 calibers long or about 270 inches). A .38 barrel is 0.38 inches in diameter

      2 years ago
    • ehung

      Hi Rick, I'm sorry but I don't have any knowledge on Navy large caliber guns!

      3 years ago
  • Joe

    Explain different kinds of hollow points like holloe point vd jhp? And xtp?

    3 years ago
    • ehung

      Hi Joe, good question…HP stands for hollow point while JHP stands for jacketed hollow point. Almost all good self-defense ammo is JHP while there’s some unjacketed lead hollow points in revolver calibers (such as .38 Special). XTP I think is just a brand from Hornady that stand for "Extreme Terminal Performance".

      3 years ago
  • Steve

    Thanks for the very good rundown on bullet types. As a total newcomer to guns, I found this page incredibly helpful. The only part I take issue with is regarding the .45 round, you say: "I can tell you from personal experience that this is not a round to hand to someone who’s never fired a gun before." I recently shot for the first time, and it was with a Colt 1911 .45 and it was frickin' awesome! I can't imagine shooting any other kind of handgun. I even hit the target (most of the time - my one-handed shooting needs work). It inspired me to set up a range on my property and I'm shooting every weekend now. Yeah, the 45 packs a wallop, but if you have a gun with enough heft, and you hold it firm, the punch is more like a push. For a first timer it might be big, but with the right instruction, it's a great experience shooting a piece of history. Thanks again for the very helpful information.

    3 years ago
    • ehung

      Thanks Steve...glad you got a good grip on the .45!

      3 years ago
  • Gray

    Thank you Eric for this great info. I'm planning to add range shooting to my hobby in the future, and thankfully I saw your article and learned a lot. My one question is, is there going to be a mixed up when buying bullets for a handgun, say I bought a certain type of bullet then later found out that it won't fit? What question should I ask the gun store when buying bullets for a particular gun if I ran out of ammo? Also, I haven't fired any gun before, so based on your article, .22 is the best for a total newbie. But I plan to get just one handgun for sport and self-defense, so I'm hoping to have 9mm instead since I don't want to own more than 1 gun. Is this okay, cost-wise (bullets)? Thanks

    3 years ago
    • ehung

      Hi Gray, you should always match the ammo to your gun. If in doubt, ask the gun store, or if you are sure of what caliber you need, check out my recs for ammo: http://www.pewpewtactical.com/best-places-to-buy-ammo-online/

      3 years ago
  • Leslie

    OMG! Finally someone who makes sense to me. Trying to learn stuff on your own or at gun shows and gun shops is wearing me down. I have been shooting all my life (north of 60 years), but being female, I get talked down to a lot and so just grab the ammo that is familiar to me and go. I have checked web sites on bullet strengths and sizes before and never got anywhere. Now I feel I have a grasp of at least the calibers you went over. I have book marked this page as I am sure I will re-read it many more times until it all stays in my memory banks. Thank you, thank you, thank you. Please do more.

    3 years ago
    • Megan

      I am also a femal shooter (only a year now) and I had the same problem. I got talked down to at a gun range. I asked questions and they would address my husband with the answers!! My husband finally had enough and we left. Thankfully I was able to find another one that has been amazing! The articles here just top off everything I've been learning and more!

      3 years ago
      • ehung

        Thanks again Megan!

        3 years ago
    • ehung

      Hi Leslie, thanks so much for your kind words. Just glad I could help someone out!

      3 years ago
  • Dave Mohler

    I recently inherited a pump action Remington 760 in 300 savage caliber without any magazines. As you can imagine not alot of places carry those magazines in that specific caliber. I was wondering if you can tell me what caliber is the closest to the 300 savage so I might be able to find a magazine the will be functional if not perfect. Thanks in advance, Dave

    3 years ago
    • ehung

      Hi Dave, hopefully this helps (http://www.gunpartscorp.com/ad/929980.htm#929990A). Looks like at least according to this the magazine is the same for .243/.308/.300 Sav

      3 years ago
  • nate

    The is a lot of history here and thank you for the time you you you you site... I do have a question though. In your breakdown of terminology (IE: five-five-six) I don't see what that means... what is 5.56 x 39?? Or 30-06??

    3 years ago
    • ehung

      Hi Nate, if you see something like 5.56x45mm, that's the dimensions of the cartridge. The 5.56 deals with the diameter of bullet while the 45 is the height of the shell. The 30-06 is a little different in that the .30 is the caliber of the bullet (size) and 06 is the year the cartridge was adopted (1906).

      3 years ago
  • JR

    I am learning about guns but having to depend on clerks in order to buy correct ammo for our guns. I have two size handguns and a variety of boxes of rounds right now. I was clueless on the differences. We also gave a shot gun. Your article was an easy read with excellent illustrations. I will check out your YouTube channel in the future...will recommend.

    3 years ago
    • ehung

      Hi JR, thanks so much and glad I could help you out!

      3 years ago
  • John T.

    Great article. It answered my question as to why the FBI went from 10mm to the .40 S&W, and now to the 9mm rounds.

    3 years ago
    • ehung

      Glad I could help!

      3 years ago
  • John

    This was amazingly written and extremely descriptive. Thank you so much!! I loved the pictures and side by sides a lining with prices. Just and all around precise and very well. Written article on caliber sizes. Thanks alot!

    3 years ago
    • ehung

      Thanks so much for the kind words, John!

      3 years ago
  • Edward J.

    Great article. Great info . Thanks

    3 years ago
    • ehung

      You're welcome!

      3 years ago
      • Kristina

        That's is an awesome article. Thank you so much. Just learning about guns and bullets. There was so much great infomation.

        2 years ago
        • ehung

          Thanks Kristina, appreciate the kind words!

          2 years ago
New to Guns ? Check out our beginners guns video course. Start Now