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Old January 19, 2013, 11:59 AM   #20
James K
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Join Date: March 17, 1999
Posts: 19,169
On the bullet shapes, I was wrong, and my apologies. Per Görtz and Sturgess, the initial concern was expressed in 1914, but it was not until 22 March 1916 that the Army order was issued that only ogival point bullets were to be produced and issued, and existing truncated cone ammo was to be used in target practice. The Navy, though, did not order the withdrawal of the cone bullet from combat use until 12 October 1918, which is where I got the 1918 and became confused.

Just FWIW, the early history of the 9mm is interesting. The original caliber for the Parabellum pistol was, as we all know, the 7.65 cartridge. Now one of the main concerns of a cartridge designer is case support (or "headspace"). The cartridge has to have a means of support against being pushed too far into the chamber and also must provide a consistent support against the firing pin blow. If the latter support is not consistent and solid, the result will be inaccuracy and misfires.

The bottleneck rifle cartridge came about because of the desire for a large powder charge while keeping the ballistically superior small caliber bullet. Originally, those cartridges retained the case rim for support. But then Mauser realized that the case shoulder could provide support and the rim eliminated. By 1900, all cartridge cases were either bottle necked or rimmed.* Some were both, but the rim provided the case support (e.g., .303 British). A bottle neck case was supported on its shoulder and could be rimless (e.g., the 8mm Mauser rifle and 7.63mm Mauser pistol). So Luger's cartridge, a modified 7.65mm Borchardt, had a shoulder and was rimless.

But German army tests showed that the small caliber was inadequate, and the army requested a caliber of 9mm. Poor Georg had problems. He wanted to retain the cartridge base size so as not to have to retool the pistol production, but when he expanded the neck of the 7.65 and left the shoulder, the shoulder was too small to stop the cartridge and to provide support. Finally, he hit on the idea of simply supporting the cartridge on the case mouth. That worked fine. But, he really should have gone to 9.5mm, because the 9mm cartridge ended up with a tapered case that has caused feeding problems over the years.

*Browning had somewhat the same problem. He started with the .32 S&W and .38 S&W cartridges and found the rimmed rounds wouldn't feed well in a magazine. So he began to cut down the rim until they worked, but the result was a semi-rimmed case in the .32 ACP and .38 ACP, with case support provided by the rim. Both rounds can have feeding problems (rim lock) in some guns. By the time he developed the .45 ACP, he was aware of Luger's system but rejected the tapered case in favor of a straight case, which has made feeding in a .45 ACP pistol or SMG much less problematical.

Jim
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