The FN 509 Midsize is a 9mm semi-automatic pistol designed to provide full-size performance in a more easily concealed package. Its four-inch cold hammer-forged stainless steel barrel uses a recessed target crown, while the polymer frame includes a MIL-STD-1913 accessory rail and interchangeable backstraps for a more secure, comfortable grip. A flatter-faced trigger, improved cocking serrations, and easily manipulated controls support confident handling. The standard configuration has no manual safety and uses 3-dot luminescent sights for quick target acquisition. Two 15-round magazines are included.

Key features

• Midsize configuration combines a four-inch barrel with a concealable frame profile
• Cold hammer-forged stainless steel barrel with recessed target crown supports durability and accuracy
• Polymer frame with interchangeable backstraps helps tailor fit and recoil control
• Flatter-faced trigger provides a consistent, controllable trigger press
• Fully ambidextrous controls support left- and right-handed operation
• MIL-STD-1913 accessory rail accommodates compatible lights and lasers

The FN 509 Midsize delivers practical capacity, controllable handling, and versatile carry-friendly performance for everyday use.