Halvor Moorshead explains that the rifle was a major improvement over the smooth-bore musket — but it suffered from a serious problem.
EARLY FIREARMS had smooth bores: the inside of the barrel was a simple long cylinder, closed at one end. During the 1500s, scoring a gently spiraling groove in the cylinder produced the first rifled barrels. A bullet fired from a rifled barrel could be made to engage the spiraled groove acquiring a spin as it traveled down the barrel. A spinning bullet is far more accurate and will travel further than a bullet fired from a smooth barrel.
The advantages of the rifle over the smooth bore musket were obvious but the rifle had a major problem. Personal fire- arms were all loaded from the muzzle end. The powder, wadding and bullet were rammed down the barrel. A round ball, as used in a smooth bore musket, was easily loaded but it was hard work to ram a bullet large enough to engage the rifled grooves down the barrel.
In the 1740s the Austrians and German states began to recruit companies of Jägers (gamekeepers) who were using rifles for hunting. The first companies were often irregulars and many were Hungarians or Croatians.
The rifle had also become popular with frontiersmen in America. Swiss and German gunsmiths in Pennsylvania developed the European rifles into the long "American" rifle. As in Europe, some of these riflemen were recruited into the colonial army to form the Royal American Regiment that later became the King's Royal Rifle Corps. The vast majority of troops still used flintlock muskets: riflemen were generally used for skirmishing and scouting.
Early rifles were accurate to 200 yards. The ball was wrapped in a piece of oiled leather that engaged the rifled grooves.
The extra range and accuracy of the rifle offered few advantages in the warfare of the 1700s. After the first few rounds had been fired, the smoke from the black powder used at the time was so thick that the troops generally could not see individual targets — it was rate of fire that mattered more than accuracy. It took a full minute to load a rifle while the musket could fire four to six shots in the same time. Muskets were so inaccurate that it was calculated that only one out of every 459 musket-balls hit its target!