[Vincine]

Is there any rhyme or reason to ammunition sizes that I seem to be missing? The range of calibers sizes appear to me fairly arbitrary. We have .17, .22, .32, .38, .40, .45 etc. The metric sized ammunition at least hits the round numbers, but they also have 5.56mm, 7.62mm among others. How come we don’t have sizes in .15, .20, .25, .30, .35, etc?

Is there some regular interval of foot pounds, or drop, or something that physics dictates these are the sizes required? I don’t see it on the ballistic charts. Is it decided by the tooling required to make the rounds? Or what?

[rjd3282]

We do have .30 that's what a 7.62 is. We have .20 as in .204, .25 as in 25 acp or 25-06, .35 as in 35 whelen.

[Rugers9]

Originally Posted by Vincine

Is there any rhyme or reason to ammunition sizes that I seem to be missing? The range of calibers sizes appear to me fairly arbitrary. We have .17, .22, .32, .38, .40, .45 etc. The metric sized ammunition at least hits the round numbers, but they also have 5.56mm, 7.62mm among others. How come we don’t have sizes in .15, .20, .25, .30, .35, etc?

Is there some regular interval of foot pounds, or drop, or something that physics dictates these are the sizes required? I don’t see it on the ballistic charts. Is it decided by the tooling required to make the rounds? Or what?

I'm not the most knowledge known guy here but I'm sure is a measure of some sort to the round.

[Vincine]

Originally Posted by rjd3282

We do have .30 that's what a 7.62 is. We have .20 as in .204, .25 as in 25 acp or 25-06, .35 as in 35 whelen.

Ah, I see. Thanks. So, where do the other 'odd' in between sizes come from?

[Rick1967]

Actually a .38 is really a .357. Hmm...perhaps I just made this a little more confusing. Sorry.

[c3shooter]

There are literally THOUSANDS of different cartridges and calibers. Some were successful, some were not. Some had a good marketing department- some did not.

5.56mm is the metric designation for .223. 7.62 is the metric .308, which is the TRUE size of the .30 cal.

Some measured from land to land, some from bottom of groove to bottom of groove. Which is why 7.62 NATO is .308, but 7.62x54R is .311.

Originally, measure was the Gauge- how many round lead balls that size to make a pound. 12 round lead balls that weigh a pound are 12 Gauge. That transitioned to muskets and early rifles.

You can find all sorts of oddball stuff if you look. I have .33 caliber rifle cartridges, .35 pistol, 14 g shotgun, .46 cal revolver, and some really weird stuff.

Borrow a copy of Cartridges of The World (large paperback, published yearly) - it is a START to introduce you to some of the stuff out there.

[Vincine]

Originally Posted by c3shooter

There are literally THOUSANDS of different cartridges and calibers. . . . (snip) . . . - it is a START to introduce you to some of the stuff out there.

Of course I hoping c3 would add his.02.

From what I just gleened from the ‘Cartridges of The World’ intro on Amazon (thanks). There isn’t any rhyme or reason to the sizes. Some names and sizes are ‘grandfathered’ in from black powder days, some names are just to be distinct from similar sized rounds made by others, some names include digits representing the year of invention. While all are made for a purpose, some more successful than others, none were/are made to evenly cover the range of ballistic characteristics and effects you’d would expect if you were starting with a white sheet.

[c3shooter]

You nailed it! Back in the black powder day, you had caliber and powder charge- as in 45-70. But then you have the 30-30, which was never a black powder round, but was sorta EQUAL to 30 grains of black. THEN the 30-06 (30 cal, made in 1906) to distinguish it from the .30 US (aka 30-40 Krag) The .38 Special- so it did not get compared to the old weak black powder .36 ball and cap. and the "fouty-faw" which is really .430, and the .50 Browning- which is NOT .50 caliber......


See? Marketing department! Myself, always liked one of the big bore straight sided rifle cartridges- the Peabody What Cheer. No, really.

[Trez]

Originally Posted by Rick1967

Actually a .38 is really a .357. Hmm...perhaps I just made this a little more confusing. Sorry.

The case is a .38...

[Trez]

When did cartridges quit being proprietary and why? I know in the old days a .38 S&W revolver shot .38 S&W and .38 Colt revolver shot .38 Colt... But now many guns shoot .38 Special (which is actually S&W Spl.) and .40 S&W, why doesnt S&W care? Or why doesnt colt make a .40 to compete? Like the olden days?

In military cartridges Ive noticed its mainly someone comes up with a better bullet design and then other countrys try to "copy" the round just with some differences so it wont shoot in the other sides guns..

Ive noticed Americans like naming their cartridges too, the metric way is so much simpler.. 7.62x54r, 7.7x58, 9x19, etc.. Caliber and case length with a little r to tell you if its rimmed.. But us Americans have .30 Winchester Centerfire (.30-30), .30 US Army/.30-40 Krag, two .30 Governments: .30 Govt. M1903; .30 Govt. M1906 - which became .30-06 Springfield, 9x19 is called 9mm Luger... Whats with all the names?

I dont have a Luger, why do I have to shoot "Luger" bullets? Or "Krag" bullets outta my Winchester??