FN America FN 509 Midsize MRD 9mm Semi-automatic Pistol Developed for the US Military's Modular Handgun System Competition-and backed by over 1 million rounds of testing in the most demanding conditions-the FN 509 represents the pinnacle of the combat pistol. It's built on the proven architecture of the FNS Compact, but every aspect-both internal and external-was scrutinized and analyzed to enhance ergonomics, ammunition compatibility, and-above all-reliability. The 509 Midsize MRD retains the 4 inch barrel of the standard 509, but features a smaller mid-size frame and all-new Low-Profile Optics Mounting System. Like the full-size 509, the barrel features a recessed target crown for enhanced accuracy, and the bore axis is extremely low. That low bore axis means recoil travels straight back into the meat of your hand, where you can best control it. The most notable improvement, though, is the Low-Profile Optics Mounting System, which allows you to directly mount 10 different popular red dots via the included plates. Adding a red dot to your carry pistol has never been easier. Low-Profile Optics Mounting System allows for easy direct mounting of more than 10 popular red dots Mid-size frame is easier to conceal than the full-size 509 Very low bore axis: recoil is directed right into the meat of your hand-not over the top of it-for better control 4 inch cold hammer-forged stainless steel barrel with recessed target crown for exeptional durability and accuracy Captive double-nested recoil spring reduces wear and enhances service life Flat-edge rear sight can be used to rack the slide one-handed in an emergency Deep-cut front and rear slide serrations for easy manipulation External rotating extractor for reliable extraction Aggressive grip texturing: deep stippling on the meat of the grip, skateboard tape-style grip at the top, Double action trigger with 5.5-7.5 lb. pull Melonite slide finish