.30 Caliber/7.62

[rojocorsa]

I was thinking....and then I asked myself, "Why is .30 cal so common in firearms today?

There are so many cartridges chambered for .30 (give or take)
For example: .30-30, .30-06, .300 Win Mag, .300 Wtby, 7.62x51 NATO, 7.62x39, 7.62x54R, 7.62x25, .30 Carbine, .300 H&H, .300 Savage, .30-40 Krag, .300 WSM,

Well, the point is, why is .30 caliber so popular?

Is there a design advantage between size or weight?
Is it convenient to manufacture?

 

[Dave R]

Dunno. There is a spectrum of cartridges from .17 to .50 (yeah, and a few beyond those.) For some reason there are clump sat .22, .30, and maybe .45. Who knows why the clumps are there?

 

[Deus Machina]

Well, for one, it's sort of traditional, since there's always been so much made for it.

Otherwise it's, IMHO, just about optimal for a rifle made to knock down North American animals, four-legged or two.

It's large enough that even the crudest versions of soft-nosed bullets can punch a wicked cavity, and small enough that it's possible to get it up to speed to do so without blowing the shooter's shoulder out.

And, if worse comes to worst and there's old FMJ being traded, I'd rather have a .30 caliber hole clean through than a .22, and it's better to put two .30-cal holes in something than a single .45.

 

[Sunray]

When all the commercial marketing BS is cut out, it's because the .30 calibre was selected as the U.S. military calibre when BP went away. Mind you, the .30 calibre bullet has certainly proved itself on game, but so did a 7mm/.284" bullet.
Trying to figure out the why's and wherefores of calibre selections can give you the same amount of brain damage as why a cartridge is called/named what it is. A whole bunch of politics is involved with some military cartirdges too.
The 7.62 and 5.56 cartridges were jammed down NATO country's throats by the U.S government. Several 7mm cartridges were being developed in the mid 50's that were ballistically better for European battlefields and nobody wanted a .223/5.56 cartridge, but the U.S. government said, "Do it or we'll cut off the money."

 

[lonegunman]

When .40 or .45 caliber rifles were the norm, .30 caliber was smallbore and high velocity.

There are two reasons why mass produced things are made the way they are made.

1. Economy of Scale. It is far easier and cheaper to make 100 variations of one diameter than to make 100 different diameters.

2. It probably has a lot to do with being able to make .30 caliber machine tools, cutters and dies with enough strength to properly cut steel and have them work properly in exisiting equipment.

I'm just guessing of course.

 

[rojocorsa]

it's because the .30 calibre was selected as the U.S. military calibre when BP went away.

Excuse my ignorance, but what is "BP" ?

Also I remeber reading somewhere that the reason that most small arms in the Soviet Union/Russia were 7.62mm was that the Soviets only needed a universal set of tools to forge bores.

All of these guns are .30:
Mosin-Nagant Family
Nagant 1895 Revolver
Tokarev TT-30/TT-33
Ppsh/PPS Family.
PPD Family
variant of Bizon sub-machine gun(7.62x25)
AK/RPK/PKM Family
DP/DPM
RPD
Dragunov/Tigr Family
SAIGA Family
SKS
SVT-40
etc.

(I like Russian Guns)

 

[Vegaslaith]

I think BP is black powder.

 

[TargetTerror]

While I'm sure that militaries having adopted 30 cal weapons played a large role in their popularity, I think there continued popularity is due to the fact that they are a good compromise between muzzle energy, exterior ballistics, and shooting comfort. There are few other calibers that can easily shoot to (or even slightly beyond) 1000 yards, dispatch a wide variety critters up to that range, and yet not knock every tooth out of the shooter on each shot.

 

[jdc1244]

Mosin-Nagant Family
Nagant 1895 Revolver
Tokarev TT-30/TT-33
Ppsh/PPS Family.
PPD Family
variant of Bizon sub-machine gun(7.62x25)
AK/RPK/PKM Family
DP/DPM
RPD
Dragunov/Tigr Family
SAIGA Family
SKS
SVT-40
etc.

Correct, as well as the 30-06/M1, British .303, German 8mm (Mauser), 7.55mm Swiss…

By the beginning of the 20th Century everyone was fielding a .30 caliber service rifle – the .30 round was just right: large enough for a one shot kill but not too large (expensive) to produce, transport, or for a soldier to carry.

 

[230RN]

OK, I'm trying to dredge this up from memory since I can't find my references.

I believe it has to do with tenths of an inch, or "lines," as in typesetting.

Thirty caliber is three lines and that was a convenient size for machining things and drilling long holes using a "gun drill" bit. This "three line" hole was then rifled, bringing, typically, the .30 "three line" rifled bore to .308 across the grooves in this country.

But "lines" varied slightly from country to country, which is why the Russian and English thirty caliber is a bit bigger than ours, groove size .311, bore size .303.

(So's the Imperial gallon (English gallon) bigger than ours --standardization was nil in those old days... remember that a "yard" was "standardized" as the length of some King's arm or some such. That was the pits in standardization.)

That's what I can remember.

I welcome being challenged/corrected on the above.

Terry, 230RN