45 auto. Underwood Ammo produces personal defense ammunition that uses the Lehigh Defense Xtreme Defense bullet. This is a CNC-machined monolithic solid copper projectile with radial flutes designed to force hydraulic energy inward, resulting in a permanent wound cavity twice that of any expanding bullet. The optimized design of the bullet maximizes penetration up to 18″. This defensive ammo is loaded with flash suppressed powder to help preserve the shooter’s vision when firing at night, and its low weight equals to high energy with lower felt recoil. Underwood Xtreme Defender is ideally suited for self-defense or hunting applications.
The .45 Auto, also known as the .45 ACP (ACP is an acronym for Automatic Colt Pistol), is likely one of the most famous American handgun cartridges of all time. It was designed by John Moses Browning in 1904 for what was an experimental semi-automatic handgun. This evolved and ultimately was adopted as the U.S. Pistol Model 1911 and its cartridge as the U.S. .45 Caliber. The U.S. M1911 in .45 Auto is one of the longest-serving handguns of the U.S. Military, with it issued from 1911 until its replacement in 1985 by the Beretta M9 9mm service pistol. Even with this “replacement”, many U.S. Special Operations Forces still used and issued the M1911 .45 caliber handgun. Recently the U.S. Marine Corps re-adopted the Colt 1911 CQBP, which is an updated 1911 for the 21st-century battlefield.
The .45 Auto cartridge is a rimless straight-wall case topped with a .451-inch projectile. Projectile weight typically ranges between 185 to 230-grains. Velocity range typically falls between 830 to 1,000 feet per second. What sets the .45 Auto apart from other handgun cartridges is its long-standing reputation as a “man stopper”. Enter any gun shop, gun forum, gun webpage and someone will likely be talking about the “stopping power” of the “Lords Caliber”, their beloved .45 Auto. So, where and how exactly did the .45 caliber initially get its reputation as a “man stopper”? During the Moro Rebellion of the Philippine-American war, it was found that the Moro tribesmen would use mind-altering drugs and wrap themselves in makeshift body armor (from tree resins and cloth). During a frontal charge on American soldiers, Moro tribesmen could take a full cylinder of the anemic .38 caliber Long Colt from the issued service revolver, showing little to no initial effect, and continue to advance.