The AR-15 chambered in 9x19mm Parabellum is an exceptional weapon system for close-quarters combat and for those looking to use the caliber for optimal suppressor use. Unlike the AR-15, the AR9's number identification indicates its caliber (9mm) in the model name. The AR platform was designed for the.223 Remington cartridge, therefore an AR9 is essentially a copy of that design modified to fire the 9mm. The reduced length of the barrel enables high maneuverability and extremely low recoil. These days, 9mm is the most common caliber for concealed carry firearms, and AR9s are typically configured to accept Glock magazines, which are widely available and very accessible. Additionally, an AR9 is a fantastic choice for home protection or as a truck gun. If you're looking for a rifle in a pistol format with a shorter barrel, that is compatible with your everyday carry handgun in terms of caliber and magazine size, an AR9 is an excellent option. AR9s are typically configured to accept Glock magazines, which are widely available, and are the caliber of choice for most concealed-carry firearms.