The Smith & Wesson M&P (Military and Police) is a polymer-framed, short recoil operated, locked breech semi-automatic pistol introduced in the summer of 2005 by the American company Smith & Wesson. It uses a Browning-type locking system. While targeted at law enforcement agencies, the M&P is also widely available on the commercial market. History The M&P is a hybrid evolution of the Smith & Wesson Sigma and Smith & Wesson SW99 design but does not share parts compatibility with the Sigma. The M&P design has an improved trigger and enhanced ergonomics that allow for end-user customization. An industry standard Picatinny rail and a higher grip has been afforded with an improved grip and beavertail. Many of the ergonomic study elements that had been incorporated into the Sigma and the Smith & Wesson SW99 were brought over to the M&P. The improved trigger weight and feel and the unique takedown method (not requiring a dry-fire pull of the trigger) were meant to set the M&P apart from the popular Glock pistols. Design details The M&P is a striker-fired semi-automatic pistol. This trigger system prevents the firearm from discharging unless the trigger is fully depressed, even if the pistol is dropped. An internal lock and/or magazine disconnect are available as options and an optional external thumb safety became available in 2009. The pistol frame is made out of Zytel polymer reinforced with a stainless steel chassis. The pistol comes with four removable and interchangeable grip inserts and features a 108° grip angle. The slide and barrel are made of stainless steel, that after hardening is treated with a proprietary nitriding process called Melonite. The Melonite process produces a matte gray non-glare surface with a 68 Rockwell C surface hardness rating. The pistol has a low slide profile which holds the barrel axis close to the shooter's hand and makes the M&P more comfortable to shoot by reducing muzzle rise and allowing faster aim recovery in rapid shooting sequence. The slide has four contact points with the frame. This was done to make the rail system self cleaning, by leaving room for any dirt or small foreign objects to fall out of the weapon. As the slide of the pistol enters battery, the striker engages the sear. At this point, the sear is held back in a partially cocked condition. When the trigger of the M&P is pulled, the trigger bar first engages