Black powder, a mixture of potassium nitrate, sulfur, and charcoal was first described and developed thousands of years ago in China. It was once then being used in firecrackers and sparingly in military weaponry. Word spread quickly of this development throughout Europe allowing for the development of firearms to begin.

Overtime firearm development greatly improved in reliability of firing, accuracy of projectile, force of projectile, and speed of firing. Firing mechanisms improved with the developments of matchlock, wheellock, flintlock, and percussion.

The force of projectile has evolved through the enhancement of kinetic energy:

KE= 1/2 MV2   
M=Mass V=Velocity

This enhancement can be seen through the increase in caliber of the weapon and or through velocity impelled by modern gunpowder.




Early Flintlock Muzzle-loader. http://www.hunter-ed.com/images/drawings/gun_parts_muzzleloader_flintlock.jpg

Today most all firearms have rifling (metal spiral grooves tin the barrel) which grip and put a spin on the bullet. This increases its accuracy and stabilization in flight. Besides Modern muzzle-loaders, most modern firearms are also breach loaded (ammo fed into chamber of the barrel from the rear). Firearms today come in all shapes and sizes (see types of firearms page) and are marketed for anything from military, personal defense, or recreational use.



Modern bolt action hunting rifle. Bolt feeds cartridge in barrel chamber.
http://www.mountainequipmentsportsblog.com/wp-content/uploads/2012/03/action.jpg