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.calibre

Discussion in 'Off Topic [BG]' started by Vorago, Mar 27, 2005.


  1. Vorago

    Vorago (((o)))

    Jul 17, 2003
    Antwerp, Belgium
    Can anyone of you gunnutters here( ;) ) tell me how the calibre measuring system works? I figured out that 1 mm is .040calibre (am I correct?), but lately I came across a site that stated that a rifle had 5.56 NATO calibre. I'm confused, what's the deal?
     
  2. one is inches, one is in mm(the calibre of the NATO round is 5.56 mm........that in inches is .223)
     
  3. DigMe

    DigMe

    Aug 10, 2002
    Waco, TX
    There are two primary methods of naming the outside diameter of the bullet. One is by naming it by tenths and hundredths of inches and the other is by millimeters. Sometimes these are combined with other aspects to make the full name of the caliber as well.

    So, a .40 caliber means that the outside diameter of the bullet is .40 inches. A 9mm means that the diameter of the bullet is 9millimeters. Often though these aren't exactly accurate. For instance .223 NATO is actually .224" and .357 magnum and .38 special actually use the same sized bullet.

    Then there are some other ones that have names with numbers based on other things.

    The .30-06 (actually with a .308 outside diam.) is the .30 caliber government round of 1906.
    The .45-70 was named in the blackpowder days when a .45-70 cartridge was a .45" bullet with 70 grains of black powder behind it.
    Then when smokeless powder was created the .30-30 Winchester was named because it had a .30 caliber bullet with 30 grains of the smokeless powder behind it. Normally though the first number or the only number is either approximately or exactly the outside diameter of the bullet.

    Yes, 1mm is about .040 or .03937. Oh yeah and 5.56 NATO is what many call the 5.56x45 cartridge, which is the European method of naming. 5.56mm is the same as .22 caliber, thus the bullet diam and the 45 is the case length in mm, much longer than a .22 cartridge case.

    brad cook
     
  4. glnflwrs

    glnflwrs

    Jan 25, 2005
    Hesperia, CA
    The 5.56 NATO round is the .224 cal m-16 cartridge.
     
  5. burk48237

    burk48237 Supporting Member

    Nov 22, 2004
    Oak Park, MI
    Actually it's a .223, no big deal, but a little warning the 5.56 nato is loaded a little hotter and not all .223's will handle, check your manual, most will but just check. Rifle rounds can really get confussing. 7mm.08= 7mm (.27 bullit) in a necked down .308 carthridge, Now we have the new short magnums .243 WSM, .270 WSM.. 7mmSTW. .300WSM, plus Weatherby made there own proprietary rounds. I have a friend who has a .375 R.D Jones It is 45.70 Case necked down to a 375 H & H packs a lot of wallop in a pistol, He uses it for Brown Bear in Alaska.
     
  6. slick519

    slick519

    Aug 11, 2001
    Salem, Or
    haha, i had such a hard time wrapping my mind all around this "caliber" naming stuff. It is really complicated! How i learned is i just bought a coffeetable book that had a bunch of guns, and started reading about them, while making rational conclusions.

    took a while... haha
    but if you are ever with a gun nut, dont try and shoot the Sh** with him by using "gun lingo" you dont know. it would be like an old guy trying to relate to his son about computers.... "hey son, say, i have about 500 rams of internets.... how many gigatids can i fit on my hardfloppy?"

    haha... hardfloppy

    slick :D
     
  7. DigMe

    DigMe

    Aug 10, 2002
    Waco, TX
    We call it .223 but the diameter of the bullet is actually .224 so he was partially right. :smug: ;)

    brad cook
     
  8. Hey Dig, I was always wondering what the "06" of 30-06 meant, thanks for clearing that up. Basically as was already stated, the common terms used for measuring bullet dimensions are often not their exact dimensions, although they're usually in the same ballpark. Another anomaly is the 8mm kurz (mauser) round which is actually 7.92mm. Also, some bullet sizes can come in all different lengths, eg "7.62mm" could mean 7.62x51mm (7.62NATO), 7.62x39mm (AK), 7.62x54R (Russian), 7.62x63mm, (30-06) etc. To further complicate things, 7.62x51/NATO can also be called .308cal. (If you're buying it commercially, it's probably going to be .308 unless it's military surpluss ammo) I think the point that I'm making is that you just need to know the terminology as the measurements aren't always exact, as was stated by others in the thread.
     
  9. slick519

    slick519

    Aug 11, 2001
    Salem, Or
    it isnt always clear.... especially when my friend came screaming at me down the range when he found out i was loading my .357mag with his .38 shells.

    "DOONT!!!"

    haha... it turns out he didnt know that both rounds are actually around .36 inches.

    extremely confusing. Especially when trying to explain it to a person who has very limited gun knowledge.

    slick
     
  10. Stinsok

    Stinsok Supporting Member

    Dec 16, 2002
    Central Alabama
    You did tell him the .357 evolved from the .38?
     
  11. You can't do it the other way around though, right? (I could be totally off here)
     
  12. Dunno what .calibre it was, but somone done shot the hell up outta a "do not pass" sign on RTE16 on my way to work...

    poor thing never saw it comin'.

    "ain't no damn sign telling ME when not to pass...blam blam blam blam blam blam blam!"

    Yes, that many times. If I have juice in my camera, I'll take a pic.
     
  13. Mike A

    Mike A Supporting Member

    Oct 3, 2002
    Kentucky
    The .357 case is 1.290" in length where the .38 Special uses a 1.155" case so that a .357 Magnum cartridge will not fit into a firearm chambered only for 38 Special. (You should always check your ammo anyway, DO NOT fire a .357 Mag cartridge in a .38 Special even if it will fit. That would be a bad thing.
     
  14. burk48237

    burk48237 Supporting Member

    Nov 22, 2004
    Oak Park, MI
    The .38 and the .357 mag are identical diameters, identical shells, but the caseing is longer on the .357, hence more omph! All .357 revolvers will shoot .38s, it is one of the selling points of the gun, cheaper practice ammo with less kick, same with .44 special and .44 mag. The reverse is not true, guns chambered specifically for .38 have shorter chambers, lighter barrels and thinner cylinder walls and won't be nice to you if you try to shoot the magnums thru them, this is ecspecially true of older revolvers or light weight models. It is real important that you don't just look at bullit diamater and shell size when determining what to put in your gun! Lots of ammo is desighned for specific feeding type wepons, for instance almost all semi-auto pistol ammo won't work in revolvers, because the casing rims are shorter and they'll fall out of the chambers. Case in point, .45 long colt and .45 A.C.P are not interchangeble, although there are some revolvers that will shoot the auto ammo with special clips as an accesscorie. Do not put ammo desighned for revolvers in semis, it will not feed ar eject, not a good thing. Guns are a lot like big Power amps, hooking it up the wrong way can cause pain! CONSULT YOUR OWNERS MANUAL!!!!!
     
  15. People of low social calibre usually get shot. :p

    Mike :D
     
  16. Ty for clarifying that!
     
  17. I'm wondering, which is more powerful out of a Magnum .357 and a Desert Eagle AE .50?
     
  18. Mike A

    Mike A Supporting Member

    Oct 3, 2002
    Kentucky
    .50 AE

    (...trying not to open that can of worms...)
     
  19. Mike Money

    Mike Money Banned

    Mar 18, 2003
    Bakersfield California
    Avatar Speakers Endorsing Hooligan
    .50 by far.


    Although, niether of them are on top of my list of things to get shot by.
     
  20. Stinsok

    Stinsok Supporting Member

    Dec 16, 2002
    Central Alabama
    I used to be the guy in the family with the most powerful handgun (.454 Casull,) but my brother in law recently got a S&W .500. I was skeptical at first, but you can get some really big bullets for that thing. Gotta get one.