Projectile, bullet
projectiles
The term ballistics is the science of projectiles and firearms. Ballistics is also known as the effects of an object being fired, whether it is a bullet, gun, or cartridge.
A round is one shot, or cartridge. The term 'round', for the projectile fired from a gun, comes from the days of the musket when the ammunition was round. The projectiles are no longer roung but the name stuck.
No, for instance a warship can fire on the move.
Weapon firing .25" projectiles
Yes, but there is a point where the round reaches the max velocity it can achieve, and any extra barrel length past that point is a bit useless.
It's called a trajectory.
Projectiles, gases, unburned powder, fire.
A gun is a projectile weapon. It launches one or more projectiles from a tube by means of gas. If the gas is produced by burning the gun is classified a firearm. If the gas is compressed by means of a spring or fed from a reservoir the gun is classified an air gun. Guns intended to be fired from the shoulder and held by both hands are called long arms. Guns meant to be operated by a single hand and lacking a stock are called handguns. Guns firing multiple projectiles consecutively by a single action of the trigger are called machine guns. Large guns mounted on vehicles, ships or fortifications are called cannons. There are also tools that are called guns because of their shape and similarity of controls to a handgun. This would include nail guns, glue guns, caulk guns, staple guns and the like.
A bullet fired from a gun
It is a gas and can be used to propel projectiles.
There are grooves in a rifle barrel, or external screw-helices on so-called Rifled slugs, which are fired from shotguns, but are externally rifled for spin stabilization?