1849 Minie bullet

The innovative gunsmith Claude-Etienne Minie was born in 1814 in Paris. After serving as an officer in the French Army, in 1849 he developed the Minie rifle and bullet.
Inaccurately pronounced minnie and incorrectly called a ball, the bullet was a cylindro-conoidal (i.e., bullet-shaped) lead projectile fired from a muzzle-loading rifle. It was small enough to fit down the J, barrel of a rifle even when fouled with burned J powder. When the rifle was fired, expanding gases entered the bullet's hollow base, pushing the outer edges into the rifling of the barrel. Since it greatly improved the accuracy, range and rate of small-arms fire, the Minie ball was rapidly adopted by the US Army. During the American Civil War, the Minie became one of the most widely used types of ammunition by the armies of the Confederacy and the Union.