The M16 rifle. It ancestor, the ArmaLite AR-15, was chambered for the 5.56x45 M193 cartridge, slightly different from 5.56 NATO loading in having a 55 grain projectile, as opposed to the 62 grain projectile of the NATO M855/SS109 cartridge. The first military rifle designed specifically to accommodate the 62 grain cartridge, however, was the FN FNC, for which the design process began in 1975, and production began in 1977.
7.62x51mm nato
Well bows and slingshots were the first use of fire arms ever. The first "GUN" was the musket and musketoon,a fire arm capable of firing anything that will fit.
It didn't replace any gun, it was the first rapid fire weapon to be made.
It was among the very first guns.
You must go into detail on what you mean by "rapid fire" in order to get an answer.
Fire lance AKA Worlds first firework and firearm
Fire lance AKA the worlds first firework and firearm
A fuse or lit splinter of wood.
The aircraft mounted machine gun was at first simply a ground machine mounted for a gunner to fire. All sides in WW1 used it. The first successful machine gun fired by a pilot was the Lewis machine gun on a special mounting attached to the top wing, allowing the gun to fire over the propellor.
the first rapid fire gun was the hand crannked gatling gun used in the civil war but the maxim was the first true machine gun which was developed not long after the gatling
China was the first to discover gun powder, is that what you mean.
the Nerf wild fire or the Nerf powerclip