03 vs 98

Because us 'Murricans don't do nothin' in fancy French measurements.
We had a .30, we kept a .30, we went to still another .30. Just what's natural.
 
Some years ago, I read an interview c. 1892 of the Army major who chose .30 for the new (Krag) rifle. The writer asked how that caliber was chosen, and admitted that he expected to hear about extensive tests and complex mathematical calculations. Instead, the officer replied that 30 caliber "seemed like a nice round number."

So much for a decision that set the U.S. rifle caliber for the next 70 years.

(And I suspect that the Germans chose 8mm for the same reason.)

Jim
 
But the German designation was originally 7.9mm; later 7.92.
And why did they ever come up with 9.3mm when 9.5 works out so well in both French and English?
 
The original German military designation was 8mm. 8x57j was the civilian designation. 8mm is .315", and that is what the original groove diameter was. The bore diameter was, and remained, .311". When the shallow grooves wore and eroded too quickly, the military changed the groove diameter spec to .323" diameter, deepening the grooves to .006" (.323"-.311"= .012"; divided by 2 = .006")

Then, for some reason, even though the 8mm had been made 8.21mm, the military chose to call it 7.9mm. This is often seen in American publications as 7.92, but the official German documents I have seen always call it 7.9. The civilian designation is 8x57js.

Jim
 
James K said:
The original German military designation was 8mm. 8x57j was the civilian designation. 8mm is .315", and that is what the original groove diameter was. The bore diameter was, and remained, .311". When the shallow grooves wore and eroded too quickly, the military changed the groove diameter spec to .323" diameter, deepening the grooves to .006" (.323"-.311"= .012"; divided by 2 = .006")

Then, for some reason, even though the 8mm had been made 8.21mm, the military chose to call it 7.9mm. This is often seen in American publications as 7.92, but the official German documents I have seen always call it 7.9. The civilian designation is 8x57js.

Jim
Click to expand...
It is called 7.9 because that's the bore diameter, 0.311" = 7.9mm; same as we call 30 cal even the groove diameter is 0.308".

I think the original groove diameter is 0.318" instead of 0.315", but I could be wrong.

It is 8x57is, instead of 8x57js; i as in Infanterie (infantry).

-TL
 
Correct on all counts.

On the change to 7.9, my sort of question was why, when they increased the bullet diameter, they decreased the numeric designation. If you go from 8mm to 8.2mm, logically you would call the new caliber 8.2mm, not 7.9mm.

On the "J" vs "I", the letters are nearly identical in Fraktur except for length; box markings in "Roman" letters vary, with some ammo makers using the "J" and others using the "I". I used the J because it is the more common today.

Jim
 
The original German designation was 8x57 I.

For Infantry. The J is an error in reading German fraktur script that has become ingrained in anglophone writings.
 
I first learned to read German printed in Fraktur, but still thought for some time that the I and J were identical. In fact the J did not exist in Latin, German or most other languages, including English, for many centuries, since words in which we now use "J" were spelled with an "I" and pronounced with an I/Y sound. German words that are now spelled with a J are usually pronounced as if it were an I or Y, as in ja and jung.

And the cartridge designation "JS" is used not only by Anglophones - some German and other European cartridge boxes use the "JS" designation. Maybe they do that only for ammunition exported to the U.S., but I have an S&B box in front of me that has "JS", not "IS".

IIRC, it was Adolf who banned Fraktur, so maybe he wasn't all bad. Today, most Germans can't read the old printing at all or can so so only with difficulty.

Jim
 
Maybe you need to check those "JS" bullets???

Here is a different story, and one I have NO PROOF of accuracy, but I offer it for its seemingly sensible explanation...

It goes like this...

When the 8mm Mauser bore diameter was changed, all the rifles in service were recalled and changed. This new size was called the 8x57 I (Infantrie).

The old smaller diameter, was still used by some makers for civilian rifles, (and for some time), and so ammo for the smaller bore size was named 8x57 J (Jaeger - Hunter)

and of course the confusion with Fraktur script was inevitable...

sounds plausible, right?
:D
 
The Germans never changed the bore on the existing rifles, all they did was change the transition cone to allow more room for the S bullet to prevent pressure spikes from the bullet touching the lands.
 
The Germans never changed the bore on the existing rifles,
Click to expand...

The bore for both barrels is/was .311, the groove diameter was different. As I have said before, closing a bolt with slight resistance is a bad habit. I know, it can only happen to me but I have fired 8mm57 70 year old ammo that reached speeds of 2,900 fps, at the same time of firing too many cases took on the appearance of gas cutting.

For my Mauser barrels, .311" is the exception.

F. Guffey
 
The original cartridge with its .318" bullet was called commercially the 8x57I (or J). The cartridge with the .323" bullet was called commercially the 8x57IS (or JS), the "S" standing for Spitzgeschoss, or "pointed bullet.")

I have seen several sources that say the Model 1898 rifles originally made for the older bullet were recalled and re-barrelled. The 1888 Commission Rifles were not rebarrelled, but a chambering reamer was run in to ream the chamber neck. (These are the ones marked with an "S" on the receiver ring; most were also converted to use the new charger (stripper clip) instead of the old en block clip.) But in most cases, sporting rifles made for the 8x57I were not converted or reamed, and many were brought back to the U.S. after both World Wars, causing problems and concerns for American ammo makers.

The leade was, of course, reamed at the same time as the chamber neck, but expanding the latter was necessary to allow the case neck to expand; if it could not, pressure increased drastically. The smaller groove diameter apparently gave no problems.

Jim
 
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