Shortening the length of the cartridge case used in the Borchardt pistol allowed Luger to improve the design of the toggle lock and to incorporate a smaller, angled grip.

Demand from Germany for a larger caliber in their military sidearm led Luger to develop the 9×19mm Parabellum cartridge for the eventual P08 pistol.

This was achieved by removing the bottleneck shape of the 7.65×21mm Parabellum case, resulting in a tapered rimless cartridge encasing a bullet that was 9 millimeters in diameter.

In 1902, Luger presented the new round to the British Small Arms Committee, as well as three prototype versions to the US Army for testing at the Springfield Arsenal in mid-1903.

[12] The name "Parabellum" is derived from the Latin motto of Deutsche Waffen- und Munitionsfabriken (DWM), Si vis pacem, para bellum ('If you want peace, prepare for war').

The .38 Special was preferred to other weapons, such as variants of the M1911, because it offered low recoil, was small and light enough to accommodate different shooters, and was inexpensive.

This, coupled with the advent of the so-called "wonder nines", led to many US police departments exchanging their revolvers for some form of 9mm semiautomatic pistols by the late twentieth century.

[16] The 9×19mm Parabellum has become the most common caliber used by US law enforcement agencies, primarily due to the availability of controllable compact pistols with large magazine capacities that use the cartridge.

[18] In 2013, a chart of popular calibers that was released by the website Luckygunner.com showed 9×19mm Parabellum as having 21.4% of the entire cartridge market, followed by the .223 Remington at 10.2% (with 5.56 mm included this is 15.7%).

In CIP-regulated countries, every pistol cartridge combination has to be proofed at 130% of this maximum CIP pressure to certify for sale to consumers.

This means that 9×19mm Parabellum chambered arms in CIP-regulated countries are currently (2014) proof tested at 305.50 MPa (44,309 psi) PE piezo pressure.

According to the 1986 book Handloading, "the modern science of wound ballistics has established beyond reasonable doubt that the 9 mm cartridge is highly effective.

With a wider selection of officers able to shoot handguns chambered in 9×19mm Parabellum, many departments chose this caliber to standardize a single firearm and loading, making logistics and supply easier.

[28] Declaration III does not apply in conflicts involving non-signatories to the Hague Convention, including paramilitary and other nongovernmental fighting forces.

While the lands of the barrel can cut into the tombac, the steel jacket resists deformation, thus causing the gas pressure to rise higher than the previous soft-jacketed m/39, giving the 7.0 grams (108 gr) bullet a Vo of 420 m/s (1,378 ft/s)[32] and an impact energy of 600 joules.

[34] The Russian military has developed specialized 9×19mm cartridges that use relatively light bullets at high muzzle velocities for both pistols and submachine guns to defeat body armor.

The increase in service pressure causes a rise in bolt thrust, so this overpressure ammunition induces more stress on critical weapon parts during firing.

[43] 9mm Parabellum ammunition is offered in a wide array of types and variations, designed to meet the specific needs and preferences of its users.