# Whats the difference between all these bullets?



## The Master

.22 9mm .757 .55 45mm 38 special, etc.

Is there an easy to understand guide for understanding the differences and compatabilities if any between different types of ammo?


----------



## Bob Hubbard

I think the size refers to the width of the bullet, and some of them have extra designations depending on the amount of powder in the casing? One of our gun experts can explain it better than me...I just used up the 5 minutes of Discovery Channel I remember.


----------



## Grenadier

The Master said:


> .22 9mm .757 .55 45mm 38 special, etc.
> 
> Is there an easy to understand guide for understanding the differences and compatabilities if any between different types of ammo?


 
45 mm would be more of an artillery shell!  

In general, American-made calibers are measured using hundredth's, sometimes thousandth's, of an inch, based on the diameter of the bullet.  Thus:

.45 ACP uses a .451" or .452" bullet
.357 magnum  uses a .357" bullet
.22 LR uses a .22" bullet
.25 ACP uses a .251" bullet

However, there are lots of exceptions, which generally outnumber the rule above.  For example:

.32 ACP uses a .312" bullet
.38 Special uses the same .357" bullet that the .357 magnum uses, but has a lesser case capacity
.380 ACP uses a .355" bullet

and so forth.  

European calibers tend to be measured using milimeters.  Thus:

9 mm Parabellum uses a 9 mm bullet
8 mm Mauser uses an 8 mm bullet


In general, the larger the caliber, the more powerful the cartridge is going to be, but as stated before, there are always plenty of exceptions.  For example, even though a .357 magnum cartridge only uses a .357" bullet, it's more powerful than a .44 Special.  

This Wiki listing:

http://en.wikipedia.org/wiki/List_of_handgun_cartridges

has quite a good list of handgun cartridges.  

and one for rifle cartridges:

http://en.wikipedia.org/wiki/List_of_rifle_cartridges

Also, remember, that rifle ammo will usually be much more powerful than handgun ammo.  This is why bullet-resistant armor designed to stop handgun cartridges is pretty much useless against any centerfire rifle cartridge.


----------



## tellner

The Master said:


> .22 9mm .757 .55 45mm 38 special, etc.
> 
> Is there an easy to understand guide for understanding the differences and compatabilities if any between different types of ammo?



What you're seeing here is calber. The caliber is the width of the bullet. .22 is twenty two hundredths of an inch. .38 Special refers both to the diameter and the length of the cartridge, as opposed to .38 Short, .38 Smith and Wesson.

9mm and 10mm also refer to the diameter of the bullet, but using metric rather than US units.


----------



## Grenadier

Also, even if a cartridge has a similar sized bullet, that does not necessarily mean that it's the same.  For example, if we look at these cartridges:

9 mm Parabellum
9 mm Dillon
9 mm Winchester
9 mm Kurz (the same as the .380 ACP)
9 mm Ultra
9 mm Makarov
9 mm IMI
9 mm Glisenti
9 mm Rimfire (yes, it does exist)

These are all different cartridges.  Some use the same 9 mm diameter bullet, but some, such as the Makarov, use a .365" bullet instead of a .355" bullet.  

Another thing, is that there can be multiple names for the same cartridge, depending on whether you're talking to an American or a European, or even between two of the same continental location.  For example:

.30 Luger = 7.65 mm Luger = 7.65 mm Parabellum
.380 ACP = 7.65 mm Browning 
.45 ACP = 11.43 mm (yes, some Euros do call it that)
9 mm Luger = 9 mm Parabellum = 9x19 mm and so forth.


----------



## The Master

And is it safe to assume that even if the diameter of the bullet is the same, the cartridges could be different widths or lengths or both and therefore are not compatable?

in other words, a 9mm Kurz won't fit in a 9mm Ultra, etc?


----------



## arnisandyz

http://science.howstuffworks.com/fr...&url=http://www.gunsandcrime.org/caliber.html


"Caliber" is the term for size designations for bullets (projectiles) and the inside diameters of the gun barrels through which the bullets are fired, as well as for the complete cartridges (rounds) and the area--called the firing chamber--in which the cartridge is inserted at the back end of the barrel preparatory to the bullet being fired out the barrel.

"Gauge" is a term for a similar purpose in relation to shot shells (for shotguns).

Caliber is expressed in units of either inches or millimeters (mm).

INCH DESIGNATIONS FOR CALIBER

A designation like .22, .25, .308, .32, .357, .38, .380, .40, .44, .45, or .50 is an expression of the approximate outside diameter, in inches, of the projectile (bullet) part of the cartridge and of the inside diameter of the barrel.  The designation typically has some word(s) or abbreviation associated with it.

For example, ".22 short" refers to a .22 caliber cartridge with a short case and a light powder load.  Other options of such .22 caliber "rimfire" cartridges include ".22 long, .22 long rifle (LR), and .22WMR ("magnum").  A .22 (caliber) rifle chambered for .22LR is commonly (but not always) able to shoot the short, rifle and long-rifle cartridges.

The case of the "magnum" is both longer than the others and has a diameter somewhat greater than the actual projectile diameter, so the magnum cartridges will not fit in a gun chambered for .22LR--and these cartridges produce considerably greater energy and projectile speeds.

The words "magnum" and "super" in caliber designations always mean more projectile energy than for cartridges without the word.  The ".357 magnum" is a caliber for a cartridge that is closely the same as the ".38 special" except for the fact that its case is longer and contains more gun powder, and therefore produces greater projectile energy than the .38 special.  The .38 special is the caliber for the revolver that was long the standard weapon for police and for civilian self protection.  It and the .357 magnum are still much used in this manner.

A .357 magnum revolver can shoot .38 special cartridges in addition to the "mag" cartridges.  This is done often for target practice because the smaller cartridges are cheaper and don't "kick" as hard.  The .357 magnum is also used for hunting by people who like to give the animal more of a chance than they would get from a hunter with a rifle (the handgun hunter has to get closer, because the handgun is not as accurate as a rifle).

A cartridge with a very slightly smaller outside diameter than the .38 special is the .380 auto for automatic and semiautomatic handguns.  The .380 cartridge case is shorter than that of the .38 special and holds less powder, so the cartridge does not produce as much energy as the .38 special.

Some of the inch calibers mentioned earlier generally refer only to cartridges for automatic or semiautomatic handguns.  For example, the .25 and .380 are common calibers for such handguns but not for revolvers.  Others calibers are common only for revolvers (like .38 special and .44 magnum).  For some, however, there are cartridges for both types of guns.  An example is ".45 Colt" for revolver and ".45 ACP" for automatic and semiautomatic.  For some numerical designations there may be several different calibers differentiated by the appended word(s)/abbreviation.

".223" is a small caliber originally developed for warfare.  ".270 Winchester" is a commonly used big-game hunting caliber.  For some numerical designations, again, there are several different calibers that are differentiated from each other with word modifiers of several types.

There are also numerous rifle calibers that are identified with usually a two digit decimal number followed by a dash or a slash, then another number.  Examples: .22-250 Remington, .30-.30 Winchester, .25/06 Remington and .30-06.  The meanings of these second numbers are not consistent.  For the "30-aught-six" the 06 refers to the year of invention, 1906.

METRIC DESIGNATIONS FOR CALIBER

Handgun calibers are commonly identified as something like "9mm Luger" or 10mm.  These both are cartridges for automatic and semiautomatic handguns.

Numbers like "7.62x33mm" are metric designations for rifle calibers.  This one is a caliber equivalent to the ".30 caliber carbine" cartridge.  The 7.62 is the diameter of the projectile in millimeters.  The "33mm" is the length of the cartridge case.  Another example is "7x57mm Mauser."

SHOTGUN AND SHOT SHELL GAUGE DESIGNATIONS

One shotgun guage, the ".410," is a decimal inch designation for inside barrel diameter (i.e., the "bore").  Other guage designations are different.  There are 10 guage, 12 guage, 16 guage and 20 guage.  The larger the number, the smaller the barrel inside diameter.  The numbers are the numbers of spherical lead balls--of diameters equal to the inside diameter of the gun--that are required to total up to a pound of lead.  The greater the barrel inside diameter, the fewer balls are required to make the pound.


----------



## The Master

Thank you.  That clears up much of this for me. :asian:


----------



## Dave Leverich

Ah! Something I didn't know about shotguns hehe, great stuff.

So say a 12-guage is .70 cal, so it takes 12 lead balls that are .7" diameter, to weigh 1 pound (roughly?). What an interesting way to measure.

The rest I was quite familiar with, but I'd always wondered on the guages.


----------



## arnisandyz

Dave Leverich said:


> Ah! Something I didn't know about shotguns hehe, great stuff.
> 
> So say a 12-guage is .70 cal, so it takes 12 lead balls that are .7" diameter, to weigh 1 pound (roughly?). What an interesting way to measure.
> 
> The rest I was quite familiar with, but I'd always wondered on the guages.



Yeah, thats how I read it too. I heard the volumetric measurement for shotguns dates back to the black powder cannons. A 12 Pounder Napoleon Cannon for example could fire a charge powerful enough to propel one 12 pound ball or multiple projectiles totallng up to 12 pounds.  Makes sense to talk about shotguns in volume because its not just the diameter, but the shot density in a 3-dimentional plane.


----------

