The iconic 1911 pistol chambered in .45 ACP is the gold standard for 1911 enthusiasts dedicated to John Browning’s original design. However, .45 ACP is not the only cartridge available on today’s market, and it may not be the best choice for your specific needs. 9mm, .40 S&W, and .22 LR are among the other cartridges available. As you continue reading our complete guide to 1911 calibers and cartridges, you’ll discover several common and uncommon 1911 calibers and which is right for your situation.