The Beretta APX RDO is an evolution of the APX striker fired pistol. The APX RDO has been developed with a cut out, on the top portion of the slide, to provide a place to mount a red dot sight to the weapon. The Beretta APX RDO striker-fired semiautomatic pistol, utilizing a removable internal metal chassis, can be easily modified with replaceable grip frame housing and is simple to disassemble and maintain. The extremely low profile, snag-free, design of the APX makes it easy to carry and draw from the holster. To accommodate right or left-handed use, the magazine release button can be easily reversed while the hold-open lever is present on both sides of the gun. Furthermore, to enhance the pistol ergonomics, the APX is fitted with quickly interchangeable backstraps of different thicknesses to accommodate most users’ grip.