Rifled musket

A rifled musket or rifle musket is a type of firearm made in the mid-19th century. Originally the term referred only to muskets that had been produced as a smoothbore weapon and later had their barrels replaced with rifled barrels. The term was later extended to include rifles that directly replaced, and were of the same design overall as, a particular model of smoothbore musket.

In the early 19th century, there were rifles, and there were muskets. Muskets were smoothbore muzzle-loading weapons, firing round 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 wall which would cause the bullet to spin as it left the barrel.

Rifles have the advantage of long range accuracy, because spinning bullets have far flatter and more stable trajectories than balls fired from smooth-bore muskets. Muskets had the advantage of a faster rate of fire. A muzzle-loaded weapon required the bullet to fit snugly into the barrel. For a smooth-bore weapon this can be a somewhat loose fit, but in the case of a rifle, the helical lands in the barrel have to cut into the bullet to make it spin. The fit needs to be sufficiently tight for the bullet to engage the rifling lands in order to impart spin; otherwise the bullet will wobble as it goes down the barrel, thus destroying its accuracy. Furthermore, if the barrel-to-bullet seal isn't tight, gases will blow through the rifling grooves and around the bullet, thus compromising muzzle velocity, accuracy and the bullet's terminal energy at the target. The greater accuracy and range made rifles ideal for hunting, but for military use the slower rate of fire was significant. The main disadvantage of rifled muskets is that the fouling caused by normal firing made them steadily more difficult to load.

Although outwardly similar, the way they were used in battle was quite different. Muskets had two functions. As firearms they delivered volleys of close range fire in close ranks. With fixed bayonets they acted much as the pikes that they replaced, using formidable line and square formations. Compared to modern weapons a musket had a limited range and slow rate of fire, meaning that the bayonet played a significant role, accounting for roughly a third of all battlefield casualties during the Napoleonic and U.S. Revolutionary War eras. Bayonets were so effective on the battlefield that often the threat of bayonets was enough to cause an enemy to turn and run. Since they were used as pikes, muskets tended to be fairly long and heavy weapons. They tended to be about four to six feet in length (six to eight feet including the bayonet), with a weight of around 10 to 12 pounds (4.5 to 5.4 kg), as longer and heavier weapons were found to be too unwieldy. The length of a musket also allowed them to be fired by rank, with no fear that the men in the rear ranks would accidentally shoot the men in front ranks in the back of the head, or, more likely, scorch their faces and burst their eardrums with the muzzle-blast. Muskets six feet in length could be fired in three ranks without fear of accidents.

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