The Other .50 Caliber


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svtruth
January 10, 2012, 01:09 PM
In reading about battleships I noticed that the guns are described as 16" 50 caliber meaning (I think) that the barrel is 50x the bore long.
Is this right?
How common is such nomenclature?
Thanks in advance.

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Der Stro
January 10, 2012, 01:22 PM
These guns were 66 feet (20 m) long—50 times their 16-inch (410 mm) bore, or 50 calibers, from breechface to muzzle. Each gun weighed about 239,000 pounds (108,000 kg) without the breech, or 267,900 pounds (121,517 kg) with the breech.[1] They fired projectiles weighing from 1,900 to 2,700 pounds (850 to 1,200 kg) at a maximum speed of 2,690 feet per second (820 m/s) with a range of up to 24 miles (39 km). At maximum range the projectile spent almost 1 minutes in flight.[1] Each turret required a crew of 94 men to operate.[1] Each turret cost US$1.4 million, but this figure did not take into account the cost of the guns themselves.[1]


http://en.wikipedia.org/wiki/16%22/50_caliber_Mark_7_gun

Seems to be a technical nomenclature, as I've always just heard them referred to as 16" guns.

Skribs
January 10, 2012, 01:33 PM
http://dictionary.reference.com/browse/caliber

the diameter of something of circular section, especially that of the inside of a tube

It's just the wording. It's 50 "diameters". Ironically, the dictionary doesn't specify inches, but somehow the gun community translated "caliber" to "inches" and uses "mm" to denote the metric system.

Migr
January 10, 2012, 01:39 PM
I was wondering the same thing. Thanks for the information.

Mike OTDP
January 10, 2012, 01:43 PM
It's pretty standard for naval guns. Usually written as 16in/50 (16 inch, 50 calibers barrel). There are often guns of the same bore diameter, but different barrel lengths. The U.S. Navy has used 5-inch guns since the 1930s - but several different types. 5 in/38, 5 in/54, and (IIRC) 5 in/62.

rodensouth
January 10, 2012, 05:00 PM
1900 pound projectile at 2690 fps!

Can you see the projectile in the air due to its large size?

GregGry
January 10, 2012, 05:42 PM
1900 pound projectile at 2690 fps!

Can you see the projectile in the air due to its large size?
Who's ready to fire it in a encore pistol? :)

SharpsDressedMan
January 10, 2012, 06:16 PM
Maybe they mean this "other" .50, the .510 Whisper. A 750gr match bullet quietly sent out to 600 yards. They quite often are made up with 16" barrels. :D ............................................................. http://i106.photobucket.com/albums/m247/matquig/510-1-1.jpg

DanTheFarmer
January 10, 2012, 06:16 PM
Hi All,

The nomenclature is common for all "big" guns. Howitzers, anti-aircraft guns, tank guns, and naval guns usually have this notion somewhere in the official name of the piece. Check out the famous German 88mm anti-aircraft/anti-tank/tank gun. It was built in a bunch of different calibers depending on the application. For example the Tiger I's 88mm was shorter than the King Tiger (Tiger II).

The US Navy's 16" guns were usually 45 caliber until the last ones built for the Iowa class had it bumped out to 50 caliber. These would be written as 16"/45 or 16"/50 respectively. Check out www.navweapons.com. There's a huge amount of information there. The figures given above for weight and fps of the shells are correct for the bombardment type HC (High Capacity) shell. The armor piercing shell likely to be used against other warships was 2700 lbs. at 2500 fps! The navy measure energy in foot-tons, not foot-pounds!

When I stood directly behind a 155mm howitzer I could see the shells heading out for quite a ways. These shell were puny compare to the 16" shells. The big boys often show up in photographs so I'm sure they would be visible to the naked eye but I can't speak from experience.

I hope I didn't ramble but I find this stuff fascinating.

Dan

jeepnik
January 10, 2012, 06:37 PM
Here's another example. This is a 3" 50 caliber. I believe it's from the USS Vestel. At any rate, it's the last one my grandfather did. Or, I should say started, sometime around 1940. I finished it in 1978.

My grandfather retired from the Navy in early 1941 on a medical. Was recalled in May or June of 1942, and passed away from a heart attack in December of 1942. His last ship was the USS Vestel before he retired.

http://i49.photobucket.com/albums/f271/Jeepnik/3INCH50CALIBER2.jpg

http://i49.photobucket.com/albums/f271/Jeepnik/3INCH50CALIBER4.jpg

MachIVshooter
January 10, 2012, 09:12 PM
Ironically, the dictionary doesn't specify inches, but somehow the gun community translated "caliber" to "inches" and uses "mm" to denote the metric system.

Caliber is not inch-specific in our lexicon. Yes, in this country, we usually dump the inch designation when referring to bore diameter in decimal inch. However, "9mm caliber" or "7.62mm caliber" is still common denotation.

Fleet
January 10, 2012, 09:21 PM
The U.S. Navy has used 5-inch guns since the 1930s - but several different types. 5 in/38, 5 in/54, and (IIRC) 5 in/62.
There was also the 5"/25, used on submarines.

Carl N. Brown
January 10, 2012, 10:08 PM
5"/25 caliber was also used pre-war (WWII) on a lot of surface ships in the anti-aircraft role, with 5"/51 cliber guns used in the anti-ship role. Then the Navy went to 5"/38 caliber dual purpose for WWII.

Army artillery used a L or length designation which meant the same as Navy caliber: length of the barrel measured a multiple of bore diameter. The main gun of the M4 Sherman was a 75 mm M3 L/40 gun

Ole Humpback
January 10, 2012, 10:29 PM
In proper English (not modern Americanized English), caliber is used to describe the land bore diameter of a firearm. In the case of a smoothbore rifle, it refers to the inner diameter of the bore. Calibre (pronounced the same as caliber) is the English word for the length of a naval gun barrel as multiples of the outer diameter of the projectile. A larger barrel calibre generally means that you can load more powder behind the projectile. When the Montana class ships were being designed, the 5" guns were upsized to allow for a true secondary battery in capital ship on capital ship engagements. They upsized them from the 5/38 used on Iowa's to 5/54's which were still in the arsenal's and not deployed at the time. The 5/54 suffered from faster rates of crew fatigue as the shells weighed nearly twice what a 5/38 shell weighed and that the 5/54 was to big for the 5/38 munition system and too small & few in deployment to justify developing a new ammo handling system for the 5/54 in the middle of WWII.

Also note that there is no such thing as a naval rifle unless you are referring to coastal defense batteries. In that sense then, the rifle is designated by the weight of the projectile fired. For instance, the US used #300 Parrot Rifles for coastal defense batteries well into the late 1800's.

Also, the Navy has always used Mega Joules as the rating for ship to ship gun weapon systems. 5" guns barely have enough energy to get into the MJ rating, but larger weapons do. The 16" Mark VII 50 Heavy Shell (the 2700lb AP round) that Iowa class ships used for engaging capital ships at range had a muzzle energy of 330+ MJ's and were capable of hitting with well over 300 MJ's at normal optical engagement ranges.

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