Field artillery in the American Civil War

At the time of the Civil War, metallurgy and other supporting technologies had just recently evolved to a point allowing the large scale production of rifled field artillery.

Further classifications of the weapons were made based on the type of metal used, typically bronze or iron (cast or wrought), although some examples of steel were produced.

[5] The smoothbore artillery was also categorized by the bore dimensions, based on the rough weight of the solid shot projectile fired from the weapon.

But the rapid expansions of both combatant armies, mass introduction of rifled artillery, and the versatility of the 12-pounder "Napoleon" class of weapons all contributed to a change in the mixed battery practices.

It was named after Napoleon III of France and was widely admired because of its safety, reliability, and killing power, especially at close range.

[7] In early 1863 Robert E. Lee sent nearly all of the Army of Northern Virginia's bronze 6-pounder guns to Tredegar to be melted down and recast as Napoleons.

The M1841 24-pounder howitzers found use in the "reserve" batteries of the respective armies, but were gradually replaced over time with heavy rifled guns.

[16] A Federal battery of four proved "highly effective" at the decisive battle of Glorieta Pass, New Mexico,[17] and Nathan Bedford Forrest frequently employed mountain howitzers for the rapid close-quarters combat that he favored.

[15] Smoothbore guns were designed to fire solid shot projectiles at high velocity, over low trajectories at targets in the open, although shell and canister were acceptable for use.

The Model 1857 was of lighter weight than the previous 12-pounder guns, and could be pulled by a six-horse draft, yet offered the heavier projectile payload of the larger bore.

During the Battle of Atlanta, a Confederate gunner was quoted: "The Yankee three-inch rifle was a dead shot at any distance under a mile.

Despite the effectiveness of this weapon, the Confederacy did produce various bronze 3" rifles and cast iron pieces with a straight tube; however, none of them were reliable and the latter were often prone to bursting at the breech.

It was used in the siege of Petersburg, Va., and was later captured on 27 April 1865, at Danville, Va., by Union troops and sent to the Ordnance Laboratory, United States Military Academy, West Point, N.Y.

The weapon uses the principle of the service revolver whereby rotation of the cylinder indexes a loaded chamber with the breech end of the barrel.

The cap is struck by a huge spring actuated striker built into the flat strip that supports the chambers at their aft end.

The lever is attached to a ratchet arrangement, the distance moved being regulated by its mounting in the frame in such a manner as to control the revolving of the cylinder.

[23] Even before the start of the Civil War, an ordnance board recommended that rifling be added to the 6-pounder field gun in order to improve its accuracy.

Hunt attempted to have the 20-pounder Parrott removed from the army's inventory, arguing that its enormous weight required a team of eight horses instead of the six needed for lighter guns, and the long range shells were of questionable reliability.

[32] Though both sides employed the 6-pounder field gun and 12-pounder howitzer in the early battles, they were recognized as inferior to the 12-pounder Napoleon and soon discontinued in the Union armies in the Eastern Theater.

Even more devastating was "double canister", generally used only in dire circumstances at extremely close range, where two containers of balls were fired simultaneously using the regular single powder charge.

Grapeshot, which originated as a naval round for cutting enemy rigging or clearing packed decks of personnel, was the predecessor of, and a variation on, canister, in which a smaller number of larger metal balls were arranged on stacked iron plates with a threaded bolt running down the center to hold them as a unit inside the barrel.

The large number of horses posed a logistical challenge for the artillery, because they had to be fed, maintained, and replaced when worn out or injured.

Horses panicked easier than men when subjected to counter-battery fire, and their movements were made difficult because they were harnessed together into teams.

Robert Stiles wrote about Union counter-battery fire striking a Confederate battery on Benner's Hill at the Battle of Gettysburg: Such a scene as it presented—guns dismounted and disabled, carriages splintered and crushed, ammunition chests exploded, limbers upset, wounded horses plunging and kicking, dashing out the brains of men tangled in the harness; while cannoneers with pistols were crawling around through the wreck shooting the struggling horses to save the lives of wounded men.The term "horse artillery" refers to the faster moving artillery batteries that typically supported cavalry regiments.

It had ample manufacturing capacity in Northern factories, and it had a well-trained and professional officer corps manning that branch of the service.

Gen. James Wolfe Ripley, Chief of Ordnance, ordered the conversion of old smoothbores into rifled cannon and the manufacture of Parrott guns.

This arrangement, championed by Hunt, allowed artillery to be massed in support of the entire army's objective, rather than being dispersed all across the battlefield.

[citation needed] Confederate cannons built in the South often suffered from a shortage of quality metals and shoddy workmanship.

Another disadvantage was the quality of ammunition as the fuses needed for detonating shells and cases were frequently inaccurate, causing premature or delayed explosions.

Coupled with the Union gunners' initial competence and experience gained as the war progressed, this led Southern forces to dread assaults on Northern positions backed up by artillery.