A series of improvements and innovations to firearms design throughout the 19th century culminated in the development of the bolt-action rifle in the late 1880's.
A rimfire percussion cap, when struck by a hammer, ignited a smokeless powder cartridge composed of copper or brass. This explosion propelled a copper-jacketed bullet out of the rifled barrel at velocities of between 2,000 and 2,800 feet per second, and was accurate at ranges of up to 1,000 yards. Another cartridge was then fed into the chamber from a spring-loaded clip via the bolt action, and the soldier was ready to fire again.
This rifle, along with larger artillery and the machine-gun, transformed the battlefield from the massed formations of Napoleon's day to the killing fields of World War I. Assaulting entrenched infantry positions became an exercise in futility until the development of the Tank and the Bomber.