Shortening the length of the cartridge case used in the Borchardt pistol allowed him to improve the design of the toggle lock and to incorporate a smaller, angled grip. Luger's work on the Borchardt design evolved into the Luger pistol , first patented in and chambered in 7. This was achieved by removing the bottleneck shape of the 7. In , Luger presented the new round to the British Small Arms Committee, as well as three prototype versions to the U. Army for testing at Springfield Arsenal in mid The Imperial German Navy adopted the cartridge in and in the German Army adopted it as well.
Here is a report on the testing of 4 different types of defense-grade ammo for the. The range was 7 yards and the test medium was 3 wet phone books back to back…. This ammo performed well, though total expansion occurred only about half the time. The other half of the time the rounds deformed into nasty looking blobs with sharp petals sticking out randomly on the sides. The rounds all fully penetrated one phone book and were found in the middle of the second book. Accuracy with this load is very good, and all rounds fired on first strike without any failures. One thing I noticed after firing is that I had a cracked case on one of the spent rounds… from the case mouth about half way down the case wall.
An armor-piercing AP shell is a type of ammunition designed to penetrate armor. Furthermore it is used to defeat concrete, ballistic vests, bulletproof glass, and other defenses. An armor-piercing shell must withstand the shock of punching through armor plating. Shells designed for this purpose have a greatly strengthened case with a specially hardened and shaped nose, and a much smaller bursting charge. Some smaller-caliber AP shells have an inert filling, or incendiary charge in place of the HE bursting charge.