The rifled barrel has been around for some time.  It is widely used in hunting, but in military and combat applications it sees limited use.  Though more accurate then a musket the rifle is slow to load on account of the need for the ball to fit snugly to the rifling.  This requires a greased ball to be virtually pounded down the length of the barrel, a task that only gets harder with each shot fired.  The build up of fouling in the barrel from each shot makes the next shot that much harder to load.  (In contrast the smooth bore musket allows balls to be dropped into the barrel with the ram rod used to tamp down the ball and wadding so the shot and powder don’t roll out the muzzle.)
The most common type at this time is the German Jaeger Rifle and various knock off copies produced by gunsmiths in other parts of Europe.  The Jaeger is short barreled (usually 22 to 30inche) large bore and somewhat heavy.  It is shorter than military musket and has no provision for a bayonet.  It is quite accurate and is very popular for big game hunting but it is not a long range gun, the Jager rifles were generally effective up to 300 yards, about three times the effective range of a muskets. 

Jaeger Rifle