Caliber clarification

Chilidogs · November 29, 2012, 09:18 PM

Can anyone give clarification on some of the varying calibers and their differences?

For example I see things like...
45 auto
45 ACP
357 Mag
357 SIG

And is there a difference between a .38 and a .380? What IS the difference if so?

Sorry for noobish question but figured you guys would be the ones that know.

Much obliged.

iraiam · November 29, 2012, 09:44 PM

45 auto and 45 ACP are the same thing, ACP stands for Automatic Colt Pistol.

.357 Magnum, This is a magnum with a bullet diameter of 0.357". This one confuses many people, a .38 special also has a .357 diameter bullet but a shorter case than the 357 magnum. (357 magnum is a 38 special with a longer cartdridge case and thus more powder)

357 SIG is basically a .40 caliber pistol case which is necked down to hold a .357 diameter bullet.

380 usually refers to a 380 ACP, 380 Auto, 9mm short, or 9 X 17, other names liekly exist for this caliber. I believe the outside diameter of the case is right about 0.380" where the bullet is seated into it.

.38 and .380, I don't have enough information to answer this question, but again the 0.380" is the diameter of the round.

There are a few different cartridges that carry 38 with them such as 38 special, 38 auto (different than 380 auto), 38 super auto.

I would suggest typing each of the calibers you want to know about into Wikipedia, the information there seems to be accurate.

I hope this helps, it can get confusing.

**44 AMP** · November 29, 2012, 09:53 PM

Cartridge names bear only a passing connection to the actual caliber. Basically the cartridge name is what ever the inventor or original manufacturer wants it to be.

Sometimes there is a historical connection, or some descriptive name, but it can simply be what the maker thought would sell best.

To answer specifics, .45 auto is the same as .45ACP. ACP stands for Automatic Colt Pistol.

.357 Magnum is NOT the same as .357 Sig. Other than the numbers (a reference to the caliber bullets fired) they are completely different cartridges, different length and shape.

A reloading manual or an illustrated catalogue from an ammo maker will give you a good comparative visual, and the reloading manuals often contain a brief history of the cartridge as well. I'm sure the info is also online, but I couldn't tell you where to find it, as I'm not well versed in what website has what....

pax · November 29, 2012, 10:08 PM

I wrote an article about this here: http://www.corneredcat.com/article/a...ber-confusion/

Hope it helps.

Kathy

Chilidogs · November 29, 2012, 10:50 PM

Perfect and thank you all very much.
Kathy I've bookmarked that...exactly what I was hoping to find.

DaleA · November 29, 2012, 11:54 PM

With Christmas coming you might want to ask someone to give you the big dog on this topic. 'Cartridges of the World'.

http://www.amazon.com/Cartridges-Wor...s+of+the+world

Take note though the book has its detractors - check the one star comments on Amazon. I think the critics have a point but it is still a tremendous reference on the topic.

And as 44 AMP said there is little reason to some of the cartridge names. They have been developed and invented over the years in many different countries when there were no 'standards' committees or regulartory boards and folks just named them whatever they wanted.

SRH78 · November 30, 2012, 01:33 AM

The vast majority of the time, 38 is a reference to the 38 special. It's actual caliber is .357 just like the 357 magnum. In fact, the 357 magnum is based on the 38 special but operates at a much higher pressure and it is a bit longer, primarily so that it won't fit in a 38 special revolver that wasn't designed for the higher pressure.

357 Sig is a very different cartridge than the 357 magnum. The 357 magnum is a much longer straight walled and rimmed cartridge designed to work in a revolver. The 357 Sig is a rimless bottle necked cartridge based on a necked down 40 Smith & Wesson cartridge and designed to work in a semi-auto pistol. It's caliber is actually .355, the same as a 9mm.

kahrguy · November 30, 2012, 10:45 AM

chillidogs please go to wikipedia or a reloading site and look up the cartidges and you will find some of what you have been told is NOT true. Just what some thing is currect. Not simple to explain the differences between cartidges and even the bullet used by like sized cartidges. .

btmj · November 30, 2012, 12:03 PM

^^ this ^^

Of course Kathy Jacksons website is a great summary. When you crave more details and history, wikipedia is a really good source.

iraiam · November 30, 2012, 12:09 PM

Quote:

chillidogs please go to wikipedia or a reloading site and look up the cartidges and you will find some of what you have been told is NOT true.

what specifically is not true above?

Gaerek · November 30, 2012, 12:12 PM

Quote:

chillidogs please go to wikipedia or a reloading site and look up the cartidges and you will find some of what you have been told is NOT true. Just what some thing is currect. Not simple to explain the differences between cartidges and even the bullet used by like sized cartidges. .

I haven't seen anything that has been mentioned that is completely incorrect. Some things have been simplified a bit, but nothing that isn't right. Please enlighten us.

Buzzcook · November 30, 2012, 01:39 PM

Quote:

Not simple to explain the differences between cartidges and even the bullet used by like sized cartidges. .

Well there is that thing called measuring.

pax · November 30, 2012, 02:01 PM

Guys,

If you find any errors in my article, please let me know -- either here, or via an email to pax at cornered cat dot com.

Thanks!

Kathy

SVO · November 30, 2012, 11:13 PM

Don't know 'bout Pax's article, but the .357 Sig is loaded with a 9mm caliber bullet (.356" dia), not a 38 caliber (.357" dia) caliber bullet. More whys? than why nots.

kahrguy · December 1, 2012, 08:02 AM

iraiam For example 380 acp does not measure 380, nothing about it does. Its only a thousands but that also the difference betwen a many others. The 357 sig is not made from 40sw brass ether and as others noted it does not use a .357 bullet. Same .355 as a 9mm but even then with some bullet makers they do list a heavier jacket on the bullet for the "sig cartidge too.
If you try it there will not be enought neck left and the brass will be shorter than needed.

Thats the reason HE and YOU should go to a reloading site or wiki page to find out what HE wants to know.

PAX Your site looks to be general enought to be full of good basic info. Nice looking site.

Archie · December 1, 2012, 10:22 PM

That is an excellent article and commentary on the subject. I was planning on writing something very much like it on my blog, but have just decided not to bother. You've done too well to attempt.

pax · December 3, 2012, 01:13 AM

Thanks for the kind words, people.

Please do let me know if you spot any mistakes, no matter how big or small they might be. It's almost impossible to proofread your own work effectively...

Kathy

iraiam · December 5, 2012, 09:00 PM

Quote:

iraiam For example 380 acp does not measure 380, nothing about it does. Its only a thousands but that also the difference betwen a many others. The 357 sig is not made from 40sw brass ether and as others noted it does not use a .357 bullet. Same .355 as a 9mm but even then with some bullet makers they do list a heavier jacket on the bullet for the "sig cartidge too.

Yep I did get my numbers mixed up, I was thinking 38 auto not 380 auto I think the actual spec may be .384 (38 auto) and not .380, see how easy it is to get confused with this stuff, thanks for the correction.

I did not say that 357 SIG was made from 40 S&W brass, I said it was "Basically a 40 caliber pistol case necked down to .357", I admit that the .357 was incorrect, and I appreciate the correction. 40 caliber does not mean 40 S&W it means 40 caliber.

I use the term "caliber" in the way it is actually defined. A bullet that measures .357 is a 35 caliber bullet, bullets that measure .308; 30 cal, 310 31cal 311; 31 cal, 312; 31 cal I guess I'm old, sorry for the confusion.

Magnum Wheel Man · December 6, 2012, 08:56 AM

BTW... a good portion of the cartridges that the numerical name is much different than the actual bullet measurement comes from the days of outside lubed bullets ( like a 22 LR ) those were heel seated... when they went away from that style of bullet, they left the case size alone, & made the bullet the size of the heel ( which was of course safe to fire in the older guns originally chambered for the cartridge, since the bullet was smaller... but the accuracy often suffered, which can give a cartridge a bad name... but that another story )

... then of course there are cartridges like 38-40, actually being 40 caliber, suposedly because they didn't want to call it 40-40 ??? there are numerous rifle cartridges whose creator wanted to use a different number than the bullets actually measure...

... even for those of us, that may have cartridge & or gun collections, seems like there is always some corn fusion between actual caliber, & the cartridge names

November 29, 2012, 09:18 PM	#1
Chilidogs Junior Member Join Date: November 25, 2012 Posts: 11	Caliber clarification Can anyone give clarification on some of the varying calibers and their differences? For example I see things like... 45 auto 45 ACP 357 Mag 357 SIG And is there a difference between a .38 and a .380? What IS the difference if so? Sorry for noobish question but figured you guys would be the ones that know. Much obliged.

November 29, 2012, 09:44 PM	#2
iraiam Senior Member Join Date: September 6, 2012 Location: Lakewood, CO Posts: 1,057	45 auto and 45 ACP are the same thing, ACP stands for Automatic Colt Pistol. .357 Magnum, This is a magnum with a bullet diameter of 0.357". This one confuses many people, a .38 special also has a .357 diameter bullet but a shorter case than the 357 magnum. (357 magnum is a 38 special with a longer cartdridge case and thus more powder) 357 SIG is basically a .40 caliber pistol case which is necked down to hold a .357 diameter bullet. 380 usually refers to a 380 ACP, 380 Auto, 9mm short, or 9 X 17, other names liekly exist for this caliber. I believe the outside diameter of the case is right about 0.380" where the bullet is seated into it. .38 and .380, I don't have enough information to answer this question, but again the 0.380" is the diameter of the round. There are a few different cartridges that carry 38 with them such as 38 special, 38 auto (different than 380 auto), 38 super auto. I would suggest typing each of the calibers you want to know about into Wikipedia, the information there seems to be accurate. I hope this helps, it can get confusing. __________________ NRA Lifetime Member Since 1999 "I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason

November 29, 2012, 09:53 PM	#3
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,791	Cartridge names... Cartridge names bear only a passing connection to the actual caliber. Basically the cartridge name is what ever the inventor or original manufacturer wants it to be. Sometimes there is a historical connection, or some descriptive name, but it can simply be what the maker thought would sell best. To answer specifics, .45 auto is the same as .45ACP. ACP stands for Automatic Colt Pistol. .357 Magnum is NOT the same as .357 Sig. Other than the numbers (a reference to the caliber bullets fired) they are completely different cartridges, different length and shape. A reloading manual or an illustrated catalogue from an ammo maker will give you a good comparative visual, and the reloading manuals often contain a brief history of the cartridge as well. I'm sure the info is also online, but I couldn't tell you where to find it, as I'm not well versed in what website has what.... __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

November 29, 2012, 10:08 PM	#4
pax Senior Member Join Date: May 16, 2000 Location: In a state of flux Posts: 7,520	I wrote an article about this here: http://www.corneredcat.com/article/a...ber-confusion/ Hope it helps. Kathy __________________ Kathy Jackson My personal website: Cornered Cat

November 30, 2012, 01:33 AM	#7
SRH78 Senior Member Join Date: April 18, 2011 Location: Texas Posts: 517	The vast majority of the time, 38 is a reference to the 38 special. It's actual caliber is .357 just like the 357 magnum. In fact, the 357 magnum is based on the 38 special but operates at a much higher pressure and it is a bit longer, primarily so that it won't fit in a 38 special revolver that wasn't designed for the higher pressure. 357 Sig is a very different cartridge than the 357 magnum. The 357 magnum is a much longer straight walled and rimmed cartridge designed to work in a revolver. The 357 Sig is a rimless bottle necked cartridge based on a necked down 40 Smith & Wesson cartridge and designed to work in a semi-auto pistol. It's caliber is actually .355, the same as a 9mm. __________________ "Those who would give up essential liberty to purchase a little temporary safety, deserve neither liberty nor safety." - Benjamin Franklin

November 29, 2012, 10:50 PM	#5
Chilidogs Junior Member Join Date: November 25, 2012 Posts: 11	Perfect and thank you all very much. Kathy I've bookmarked that...exactly what I was hoping to find.

November 29, 2012, 11:54 PM	#6
DaleA Senior Member Join Date: September 12, 2002 Location: Twin Cities, MN Posts: 5,310	With Christmas coming you might want to ask someone to give you the big dog on this topic. 'Cartridges of the World'. http://www.amazon.com/Cartridges-Wor...s+of+the+world Take note though the book has its detractors - check the one star comments on Amazon. I think the critics have a point but it is still a tremendous reference on the topic. And as 44 AMP said there is little reason to some of the cartridge names. They have been developed and invented over the years in many different countries when there were no 'standards' committees or regulartory boards and folks just named them whatever they wanted.

November 30, 2012, 10:45 AM	#8
kahrguy Senior Member Join Date: October 1, 2012 Posts: 561	chillidogs please go to wikipedia or a reloading site and look up the cartidges and you will find some of what you have been told is NOT true. Just what some thing is currect. Not simple to explain the differences between cartidges and even the bullet used by like sized cartidges. .

November 30, 2012, 12:03 PM	#9
btmj Senior Member Join Date: November 1, 2011 Location: Near St. Louis, Missouri Posts: 864	^^ this ^^ Of course Kathy Jacksons website is a great summary. When you crave more details and history, wikipedia is a really good source.

November 30, 2012, 02:01 PM	#13
pax Senior Member Join Date: May 16, 2000 Location: In a state of flux Posts: 7,520	Guys, If you find any errors in my article, please let me know -- either here, or via an email to pax at cornered cat dot com. Thanks! Kathy __________________ Kathy Jackson My personal website: Cornered Cat

November 30, 2012, 11:13 PM	#14
SVO Senior Member Join Date: December 20, 2009 Location: Texas Gulf Coast Posts: 728	Don't know 'bout Pax's article, but the .357 Sig is loaded with a 9mm caliber bullet (.356" dia), not a 38 caliber (.357" dia) caliber bullet. More whys? than why nots.

December 1, 2012, 08:02 AM	#15
kahrguy Senior Member Join Date: October 1, 2012 Posts: 561	iraiam For example 380 acp does not measure 380, nothing about it does. Its only a thousands but that also the difference betwen a many others. The 357 sig is not made from 40sw brass ether and as others noted it does not use a .357 bullet. Same .355 as a 9mm but even then with some bullet makers they do list a heavier jacket on the bullet for the "sig cartidge too. If you try it there will not be enought neck left and the brass will be shorter than needed. Thats the reason HE and YOU should go to a reloading site or wiki page to find out what HE wants to know. PAX Your site looks to be general enought to be full of good basic info. Nice looking site.

December 1, 2012, 10:22 PM	#16
Archie Senior Member Join Date: May 26, 2000 Location: Hastings, Nebrasksa - the Hear Posts: 2,209	Miss PAX; That is an excellent article and commentary on the subject. I was planning on writing something very much like it on my blog, but have just decided not to bother. You've done too well to attempt. __________________ There ain't no free lunch, except Jesus. Archie Check out updated journal at http://oldmanmontgomery.wordpress.com/

December 3, 2012, 01:13 AM	#17
pax Senior Member Join Date: May 16, 2000 Location: In a state of flux Posts: 7,520	Thanks for the kind words, people. Please do let me know if you spot any mistakes, no matter how big or small they might be. It's almost impossible to proofread your own work effectively... Kathy __________________ Kathy Jackson My personal website: Cornered Cat

December 6, 2012, 08:56 AM	#19
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	BTW... a good portion of the cartridges that the numerical name is much different than the actual bullet measurement comes from the days of outside lubed bullets ( like a 22 LR ) those were heel seated... when they went away from that style of bullet, they left the case size alone, & made the bullet the size of the heel ( which was of course safe to fire in the older guns originally chambered for the cartridge, since the bullet was smaller... but the accuracy often suffered, which can give a cartridge a bad name... but that another story ) ... then of course there are cartridges like 38-40, actually being 40 caliber, suposedly because they didn't want to call it 40-40 ??? there are numerous rifle cartridges whose creator wanted to use a different number than the bullets actually measure... ... even for those of us, that may have cartridge & or gun collections, seems like there is always some corn fusion between actual caliber, & the cartridge names __________________ In life you either make dust or eat dust...

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