Colt AR15 A4
Colt AR15 A4. A rifle (Colt AR15 A4 5.56 Rifles for sale-Buy Colt AR15 A4 5.56 Rifles-buy ar 15 rifle) is a portable long-barrelled firearm designed for precision shooting, to be held with both hands and braced against the shoulder during firing, and with a barrel that has a helical pattern of grooves (“rifling“) cut into the bore walls. The term was originally rifled gun, with the word “rifle” referring to the machining process of creating grooving with cutting tools, and is now used for any long handheld device designed for aimed discharge activated by a trigger, such as air rifles and the personnel halting and stimulation response rifle. Rifles are used in warfare, hunting and shooting sports.
Like all typical firearms, a rifle’s projectile (bullet) is propelled by the contained deflagration of a combustible propellant compound (originally black powder, later cordite, and now nitrocellulose), although other means such as compressed air are used in air rifles, which are popular for vermin control, hunting small game, formal target shooting and casual shooting (“plinking“). The raised areas of the rifling are called “lands,” which make contact with the projectile, imparting a spin around the longitudinal axis of the barrel. When the projectile leaves the barrel, this spin lends gyroscopic stability to the projectile and prevents tumbling, in the same way that a properly spirally thrown American football or rugby ball behaves. This allows the use of aerodynamically-efficient bullets (as opposed to the spherical balls used in muskets) and thus improves range and accuracy.
Formerly, rifles only fired a single projectile with each squeeze of the trigger. Modern rifles are capable of firing more than one round per trigger squeeze; some fire in a fully automatic mode and others are limited to fixed bursts of two, three, or more rounds per squeeze. Thus, modern automatic rifles overlap to some extent in design and function with machine guns. In fact, many light machine guns (such as the Russian RPK) are adaptations of existing automatic rifle designs. A military’s light machine guns are typically chambered for the same caliber ammunition as its service rifles. Generally, the difference between an automatic rifle and a machine gun comes down to weight, cooling system, and ammunition feed system. Rifles, with their relatively lighter components (which overheat quickly) and smaller capacity magazines, are incapable of sustained automatic fire in the way that machine guns are; they trade this capability in favor of increased mobility. Modern military rifles are fed by magazines, while machine guns are generally belt-fed. Many machine guns allow the operator to quickly exchange barrels in order to prevent overheating, whereas rifles generally do not. Most machine guns fire from an open bolt in order to reduce the danger of “cook-off”, while almost all rifles fire from a closed bolt for accuracy. Machine guns are often crewed by more than one soldier; the rifle is an individual weapon.