Bullets for Beginners

 

Guns are generally classified according to use, size, and tradition. This varies among the military services. The soldier's individual weapons consist in most countries of an assault rifle in caliber 5.56 or 7.62 mm. Light support weapons consist of machine guns, single shot grenade launchers and automatic grenade launchers. Machine guns are available in caliber 5.45, 5.56, 7.62, 12.7 and 14.5 mm.

Rifle - A rifle is a shoulder firearm weapon that fires a bullet through a rifled barrel 16 inches or longer. The rifling or grooves in the bore cause the bullet to spin providing stability and extended range.

 

Carbine - A carbine has a barrel under 16 inches in length Accuracy and ballistics tend to be inferior to the full version of the rifles they are adapted from.

 

Assault Rifle - Rifles capable of single shot or automatic fire using a short cartridge providing accurate fire and more controllable recoil force than a standard rifle cartridge. By reducing the cartridge case length and ammount of powder, the cartridges weigh less and more can be carried. These shorter rifles were developed in response to the recognition that most fire-fights take place at ranges under 400 yards. The small size of the assault rifle and its ability to fire at up to 800 rounds per minute has led to it being adopted by various forces as a replacement for the submachine gun.

Bullets can be optimized for minimum time of flight, minimum dispersion, maximum retained kinetic energy, minimum cross wind sensitivity, minimum ballistic drop, maximum penetration, and limiting maximum range. For instance, a heavier bullet launched at lower muzzle velocity is a bullet designed to minimize cross wind sensitivity. As the bullet gets heavier, more of the projectile body can be dedicated to ogive length, reducing drag. Heavier, faster, lower drag is generally better, but with a fixed case volume, it is not possible to improve all of these attributes simultaneously. A bullet optimized for one parameter is often the worst solution for another important parameter. Optimizing one parameter requires compromise on others.

A complete round of small-arms ammunition is known as a cartridge, and is made up of the following components:
 

Bullet: The bullet in general is cylindrical. The nose may be round, as in the cal, .50 bullet, or ogival as in all service rifles and machine gun bullets. The base may be square or boattailed.

Cartridge case: The cartridge case is the means whereby the other components are assembled into the unit. It also provides a waterproof container for the propelling charge.


Primer: Percussion
 

Powder: The powder consists of a quantity of smokeless powder. The weight of the charge is not constant. It is different for each powder lot to give the required velocity with pressure within the limits prescribed for the weapon in which it is fired.