Wikipedia
The long rifle, also known as longrifle, Kentucky rifle, or Pennsylvania rifle, was one of the first commonly used rifles for hunting and warfare. It is characterized by an unusually long barrel, which is widely believed to be a largely unique development of American rifles that was uncommon in European rifles of the same period.
The longrifle is an early example of a firearm using rifling, spiral grooves in the bore. This gave the projectile, commonly a round lead ball, a spiraling motion, increasing the stability of the trajectory. A more stable trajectory meant dramatically improved accuracy over the more commonly available smooth bore muskets also used in the period. Rifled firearms saw their first major combat use in the American colonies during the French and Indian War, and later the American Revolution in the eighteenth century.
Until the development of the Minié ball in the middle of the 19th century, the main disadvantages of a rifle compared to a musket were a slower reload time due to the use of a tighter fitting lead ball and greater susceptibility to the fouling of the bore after prolonged use - such fouling would eventually prevent loading altogether, rendering the weapon useless until thoroughly cleaned. The adoption of the Minié ball essentially nullified these disadvantages and allowed the rifle to completely replace the musket.
The longrifle was made popular by German gunsmiths who immigrated to America, bringing with them the technology of rifling from where it originated. The accuracy achieved by the longrifle made it an ideal tool for hunting wildlife for food in colonial America.
The American Longrifle, more commonly, but less correctly, known as the 'Kentucky rifle', was described by Captain John G. W. Dillin in the dedication to his seminal 1924 book, The Kentucky Rifle:
Usage examples of "long rifle".
This time he did not, and he leaned the long rifle against the wall instead of hanging it over the chimney board where it would be closer to the half-breed than to its owner across the room.
The rifle was fifty-four dollars and fifty cents--he wanted to sell her a four-power telescopic sight as well, which she refused--and a box of fifty long rifle .
The young private sighed audibly, then withdrew his long rifle—.
Old Shadrach raised his long rifle in case Buffalo Hump strayed in range, but he didn't expect it, and he didn't fire.
He carried a long rifle, the stock of which he set against the ground.
The action was about three long rifle-shots from the southern rim, and as many more from his present position.
The Skinner chief grunted again and leaned on his long rifle, making a motion with one hand.
The long rifle-muskets came up to their shoulders with a jerk, like a centipede rippling along the line.
A long rifle barrel protruded from behind a tree, The marksman kept undercover, but there was little question he was the person they were pursuing.