In the early 19th century, there were rifles, and there were muskets. Muskets were smoothbore muzzle-loading weapons, firing round lead balls or buck and ball ammunition, that were also designed to accept a bayonet. Rifles were similar in that they used the same kind of flintlock or caplock firing mechanism, but the main difference was that their barrels were rifled – that is, their barrels had grooves cut into the interior surface which would cause the bullet to spin as it left the barrel.