AR15M16style

AR-15/M16 style refers to a family of lightweight, magazine-fed rifles and carbines built around a common receiver design that originated in the United States. The platform is modular, with interchangeable upper and lower receivers that allow different lengths, calibers, and accessories. Most designs are gas-operated and air-cooled, and use a telescoping buttstock and detachable box magazines. While many models employ a direct gas impingement system, some variants use a short-stroke piston system.

Historically, the design traces to the late 1950s when Armalite developed the AR-15 chambered in 5.56x45mm NATO. Colt produced military variants and marketed civilian semi-automatic versions. The US military adopted the select-fire M16 rifle in the 1960s, with later models such as the M16A2 and M16A4 introducing improved sights, controls, and modular rails. The family also includes carbine variants and derivatives like the M4, which features a shorter barrel and enhanced rail systems.

Caliber and operation are central to the AR-15/M16 style. The core military cartridge is 5.56x45mm NATO, while civilian variants are typically chambered in .223 Remington. Numerous other calibers have been developed for the platform. Magazines commonly hold 20 or 30 rounds, with configurations and accessories expanding through rails and mounts to support optics, lights, and other gear.

Variants and use: In civilian markets, AR-15 refers to semi-automatic variants, whereas M16 denotes military select-fire rifles. The family is widely used for sport shooting, competitive events, and hunting, and remains a major platform for firearm production. Laws and regulations affecting features and configurations vary by country and region.