While the Sig Sauer P226 is used by many militaries and agencies worldwide, one of the most famous users of the pistol is the U.S. Navy SEALs, which used the P226 up until they switched to the Glock 19 around 2015. But the pistol has constantly evolved throughout its service with the Navy SEALs: there are three practical generations of P226s that have been used by the SEALs.The first generation of P226 was adopted by the Navy SEALs following some embarrassing issues that happened during the XM9 pistol trials that resulted in the adoption of the Beretta 92 by all services. A slide on a Beretta failed and hit a Navy SEAL in the face, causing him minor injury. While Beretta would address this flaw in the issued version of the M9, the damage was already done, and the SEALs chose the P226, a runner up design, as their primary service pistol.However, poor experiences with 9mm ball ammunition would lead special units to develop the Mk 23 Offensive Handgun Weapon System, chambered in .45 ACP. These hulking pistols would go on to be used by the Navy SEALs, under the designation Mk 23, but was soon found to be too big and heavy for practical use. So, in the late 1990s, the Navy decided to buy more P226s, but designated them Mk 24, as they were the next pistol adopted after the Mk 23.The Mk 24 differed from earlier P226s as it was purpose built for the SEALs and the demands for their environment, featuring a chrome lined chamber and barrel, a proprietary Sig rail and a new finish on the slide. The characteristic anchor was also present on the slide, indicating that the pistol was purpose-built for Naval Special Operations Forces.