What are they in metric?


May 3, 2006, 10:43 AM
I'm trying to educate some friends on various calibers however I keep running into one problem. Simply put I can't find the full metric measurements for most calibers I need.

Here is a list of the ones I need, .22LR, .38 Special, .380 ACP, .45 Long Colt, .45 ACP, .44 Magnum, .454 Casul, .50 AE, .40 S&W, 10mm Auto, .303 British, .30-30, .30 US Carbine, .30-06, and .50 BMG.

For those of you who might know what I need, but not what I mean, an example of the format I'm looking for is 7.62x51, not 7.62 Nato.

Thanks in advance.

Edited at 10:18 AM Sorry I forgot to mention that I also need cartrige length. Thanks for the help so far [/I]

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May 3, 2006, 10:44 AM
1 inch = 25.4mm, so if you know actual bullet diameters you can convert. I'm not sure that helps you though.

May 3, 2006, 10:52 AM
which converts lots of measurements to lots of others


May 3, 2006, 11:03 AM
You can use google to do conversion also. just search for something like "Fourty inches to meters" or "Twelve quarts to liters", you might need to use 40/12 instead of spelling it out, can't remember. You can also do this on your cell phone! Send a text message to 466453 (GOOGLE). I use it at the range when I need to convert between metric sights and the ranges we shoot at in my club.

Creeping Incrementalism
May 3, 2006, 11:05 AM
Don't forget that the name of the cartirdge only gives you a vague idea of the bullet diameter. I'd check a reloading manual to get the actual dimensions in English units.

From memory, wich may be wrong, 22LR is .224, .38 is .357, .45ACP is .451, 44 Magnum is .429, 50AE is a true .500, .40 S&W and 10mm are a true .400, .303 is .311, .30-30 & 30 carbine & .308 & 30-06 are all .308, and .50BMG is .510. I don't know what 380 is, .355-.357 or something like that.

May 3, 2006, 11:12 AM
9mm is .355, essentially the same diameter as a .38/.357 (couple thousandths off).

Matt G
May 3, 2006, 11:13 AM
.22 = [(.223" = 5.6642 mm) or (.224" = 5.68959mm)]
.38 Special = (.357" = 9.067799999999998 mm)
.380 ACP = (.355" = 9.017mm)
.45 Long Colt (.451" = 11.4554mm)
.45 ACP "
.44 Magnum (.429" = 10.8966mm)
.454 Casul
.50 AE (.50" = 12.7mm)
.40 S&W (.40" = 10.16mm)
10mm Auto "
.303 British (.311
.30 US Carbine
.50 BMG

May 3, 2006, 12:09 PM
Check the Lyman reloading manual. I believe that is lists cartridges by their U.S. name, and below that lists the metric designation. For instance .30-30 is the U.S. name, metric is 7.62x51R

May 3, 2006, 12:11 PM
.30-06 = 7.62 x 63

May 3, 2006, 12:44 PM
.22LR, .38 Special, .380 ACP, .45 Long Colt, .45 ACP, .44 Magnum, .454 Casul, .50 AE, .40 S&W, 10mm Auto, .303 British, .30-30, .30 US Carbine, .30-06, and .50 BMG

.22LR=UNKOWN (I have only seen it referred to .22, even on foreign ammo and sites)
.38 Special= 9x29mmR
.380 ACP= 9x17mm commonly called 9mm Short/ Corto/ Kurz
.45 LOng Colt=UNKOWN
.45ACP= 11.43x23mm
.44 Magnum=10.92x33mmR
.454 Casual=UNKNOWN
.40 S&W= UNKNOWN (.40=10mm)
10mm Auto= 10mm is metric already!
.303 British=7.7x56mmR
.30 US Carbine= 7.62x33mm

UNderstanding nomenclature:
Example: 7.62x54mmR-7.62=diameter of bullet:54=case length mm=units R= Rimmed

May 3, 2006, 01:08 PM
.223 is 5.56 :D :what:

and .22 is also 5.56, because we use .22 conversions of the SA 80 rifle occasionally, it fires a 5.56, however you can shoot 22 thru it (the conversion kit is very cool it has a little insert which is shaped exactly like 5.56 and it is the only semi auto .22 i have ever seen

Jim K
May 3, 2006, 01:32 PM
FWIW, the .22 LR in Germany is called the .22 LfB or "Lang fur Buchsen" ("long for rifles"). The military designation was/is 5.6mm LfB.

MP510 has most of the others and Firehand has correctly called the .30-30 the 7.62x51R. (The "R" is important - 7.62x51 is the 7.62 NATO or .308 Winchester.) The blanks in MP510's list are either because the cartridge is not in use in Europe or was never made there and ammunition is imported from the U.S. along with its American name.

Two other calibers that were very popular in Europe were given Metric designations. The .22 Hornet is the 5.6x36R, and the .22 Savage High Power is 5.6x52R.

Not all cartridges were commonly called by the full metric designation but used the name of the gun or the inventor. Examples are the 6.35 Browning (.25 ACP), 7.65 Browning (.32 ACP), and the 9mm Browning Short (.380 ACP), 9mm Parabellum (9x19 or 9mm Luger). In addition, some companies, like DWM, gave each cartridge a number, which was used in the catalog, the box and often the headstamp. For example, the 9mm Browning Short was DWM 540.


May 3, 2006, 03:11 PM
5,6 mm is how it's called in all the ammo I buy. No special characters afterward.

May 3, 2006, 03:32 PM
I believe the full metric for the .223 is 5.56x45mm, the second being the length of the case in mm

May 3, 2006, 09:02 PM
1mm = .03937", so you can multiply out any decimal to metric

May 3, 2006, 10:19 PM
"...you can multiply out any decimal to metric..." Which has nothing to do with the metric(read European) name of any cartridge. .308 Win, for example, doesn't convert to 7.62mm. It converts to 7.82mm. Trying to figure out the why's of cartridge names can give you brain damage.

May 3, 2006, 11:39 PM
Off the top of my head:

.50bmg: 12.7x99
.45acp: 11.4x23
10mm: 10x25mm
8mm Mauser: 7.92x57
9mm Makarov: 9x18

As for the first three, I can't say I've ever seen them commonly referred to by those names, but it does point out one nice thing about the metric naming convention, assuming the measurements are roughly correct - it does give one at least a broad idea of the cartridge's overall size and powder volume. Not nearly precise enough to prove anything or assume cartridge compatibility, but a handy mental index.

On a side note, a gunshop employee once told me that he had a customer who thought a .38 revolver could also fire .308 - I guess because both calibers contained a "3" and an "8". Needless to say, gun users should educate themselves about which calibers are compatible and which most emphatically aren't, but the total mess of cartridge nomenclature does not make things easy for those who aren't detail-oriented.

May 4, 2006, 03:21 PM
This is a good place to find the actual measurements: http://stevespages.com/page8d.htm

But the actual measurements don't necessarily have anything to do with the names. As others have said, these are names, they don't have to make sense.

Some are based on bore diameter, some on bullet diameter. The .308 has been mentioned. The American name is based on bullet diameter, .308" (7.82mm), the NATO designation is based on bore diameter, 7.62mm (.300"). For the same reason 8mm Mauser (8x57) is usually called "7.92" in Norway...

I'm European. I don't know the "European" designations for most of the cartridges you ask about. Norway may be different from for example Germany, but no one here ever refers to an American or British cartridge by a metric name, with a couple of exceptions such as the 7.62 or 5.56 NATO which are known by both names. The .30-06 was called 7.62x63 by the military when we used it as a military round. I've never heard anyone refer to it as anything but .30-06 in a civilian context, though most knowledgeable shooters will recognize both names.

If you walk into a Norwegian gun store and ask for a box of 7.62x51R, it is a very safe bet that you will be handed a box of .308. If you then specify the R, the clerk will probably either admit ignorance or deny that any such thing exists. If you ask for .30-30 he will instantly know what you're talking about even though it isn't a very popular round here.

European made ammunition in "American" calibers is sold with the original name on the box, just as American made 9mm is called 9mm, not ".355 Auto" or some such. Exceptions may be some military designations and ammo that was "originally" made on both sides of the pond, such as .32 ACP/7.65mm.

Not nearly precise enough to prove anything or assume cartridge compatibility, but a handy mental index. I have seen a few empty cases on Norwegian rifle ranges, usually just before hunting season, that are commonly referred to as "7.62 Idiot". Those are "fireformed" .308 cases with the neck and shoulder blown out from being fired in a .30-06 rifle.

.50 BMG is usually known as "tolv-sju" in Norwegian, that translates as "twelve-seven". Some geezers like my father may call it "halv-toms" or "half-inch".

Carl N. Brown
May 4, 2006, 05:57 PM
A few I had on hand:
.22 Savage Hi-Power (5.6x52R) .227
.30 US Carbine M1 (7.62x33mm) .308
.303 British (7.7x56R) .312

May 4, 2006, 10:08 PM
M67: "7.62 Idiot", that's pretty good. Just to be clear, when I said "handy mental index" I meant in terms of reading cartridge dimensions (in a book or on a website) and making a rough guess as to their power compared to other cartridges, not in terms of any "hands-on" activity such as reloading.

May 5, 2006, 08:43 AM
I was under the impression that some of the designations aren't particularly accurate. For example, 9mm Makarov's actual bullet diameter is .363 rather than .355.

Also, I recall .44 Magnums actually use a bullet diameter of .429, which is 10.9mm.

Carl N. Brown
May 5, 2006, 11:29 AM
The .38-40 and .44-40 for instance did hold a nominal charge of 40 grains BP, BUT .....
The .38-40 bullet is actually closer to .40 inch.
The .44-40 bullet is actually closer to .42 inch.

Apparently marketing decided .40-40 and .42-40 just did not sound right.
And 10mm-40 and 10.5mm-40 would just be bizarre.

7.62x54R Mosin-Nagant is 7.62mm .308 inch land-to-land or
7.7mm .312 inch groove to groove, which is why .310 or .311 inch
bullets work so well. And individual barrels will vary.

My 7.63mm .30 inch Mauser pistol barrel is worn out, will not stabilize a
standard 7.62 Tokarev or 7.63 Mauser bullet (.307 to .308 inch), but
shoots my reloads with .312 inch diameter ".32 H&R Magnum" bullets
just fine. Individual barrels will vary from the factory, adding to the fun.

Carl N. Brown
July 6, 2006, 05:10 PM
European singleshot rifle markings:
7.65mm = .32-20 Winchester
7.60mm = .30-30 Winchester

Grape Ape
July 6, 2006, 09:56 PM
It might be more useful to look at the ammunition manufacturers' websites (winchester.com is pretty nice). They will give you the trajectory, velocity and energy for the various bullet weights and calibers.

After all .30-30 and .308 both measure 7.62x51, but the later is significantly more powerful than the former.

July 8, 2006, 09:54 PM
Also, to further confuse issues, often especially for older less popular cartridges, at one time bullet of diameter XXX was used, but now they use bullet of diameter XXY, because some much more popular loading uses that and they just use that same one rather than making very small amounts of the older original one

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