Backdating enfield rifle musket
Weapons like the Springfield Model 1868 were produced by simply changing out the lock mechanism of a rifled musket.
However, once this change was made, the weapon was no longer referred to as a rifled-musket and was instead referred to as simply a "rifle".
This potential accuracy, however, required skills only acquired through advanced training and practice; a rifle-musket in the hands of a raw recruit would not have performed very much better than a smoothbore.
In the 1850s and 1860s, new weapons produced with rifled barrels continued to be referred to as "rifled muskets" or "rifle-muskets" even though they had not originally been produced as smoothbore weapons.
Muskets had the advantage of a faster rate of fire.
Muskets had two functions - as firearms they were used to deliver volleys of short-range fire in close ranks, and with fixed bayonets they were used much as the pikes they replaced, using formidable line and square formations. Bayonets were so effective on the battlefield that often the threat of bayonets was enough to cause an enemy to turn and run.
The loose-fitting ball in a smoothbore musket was accurate to ranges of 50 to 75 yards (46 to 69 m) or less.
Rifled muskets increased the effective range to about 200 to 300 yards (180 to 270 m), and in the right hands could often hit a man-sized target up to 500 yards (460 m) away.
When the weapon was fired, the skirt expanded to fit tightly against the inside of the rifle barrel, with less energy wasted in blow-by around the projectile and insuring that the rifling lands and grooves would impart a stabilizing spin to the minié ball.
In the 1840s and 1850s, many smoothbore muskets had their barrels replaced with similar barrels that were rifled so that they could fire the new bullet.
The term was only used for weapons that directly replaced smoothbore muskets.