Like other Parrott rifles, the gun breech was reinforced by a distinctive band made of wrought iron.

Cannons needed to be strong enough to withstand the explosion that reduced the gunpowder charge to propellant gas.

Bronze smoothbore cannons were in need of a larger gunpowder charge because there was windage – or space – between the shot and the barrel.

With rifled cannon, the ammunition was designed to expand the shell so that there was no windage between the projectile and the gun barrel.

[2] In 1836, when Robert Parker Parrott was an ordnance officer in the U.S. Army, he resigned to take a job with the West Point Foundry in Cold Spring, New York.

Parrott attempted to solve this dilemma by inventing a cast-iron rifled cannon that had a wrought-iron reinforcing band wrapped around the breech.

The West Point Foundry helped the Federal war effort to such a degree that a joke made the rounds that the U.S. national emblem should be changed from an eagle to a parrot.

[9] On 24 September 1863, the Ordnance Board recommended that production of the 2.9-inch Parrott be halted and that existing guns be re-bored to 3-inch caliber.

The West Point Foundry halted production of 2.9-inch Parrott rifles on 13 April 1863 and the 3-inch versions did not appear until 12 February 1864.

The artillery piece was put through trials by none other than Thomas J. Jackson, a little-known Virginia Military Institute professor who later became the famous general.

[9] With the outbreak of war, the Tredegar Iron Works began manufacturing a copy of the 2.9-inch Parrott rifle for the Confederacy.

Reading & Brother of Vicksburg, Mississippi, Street, Hungerford & Jackson of Memphis, Tennessee, and Bujac and Bennett of New Orleans.

The gunpowder charge weighed 1.0 lb (0.5 kg) and fired the projectile with a muzzle velocity of 1,230 ft/s (375 m/s) to a distance of 1,850 yd (1,692 m) at 5° elevation.

[14] A smoothbore cannon's projectile typically retained only one-third of its muzzle velocity at 1,500 yd (1,372 m) and its round shot could be seen in the air.

Tumbling occurred when the shell failed to take the grooves inside the gun barrel or when the spin wore off in flight.

In particular, the Parrott rifle's gaining twist caused the Hotchkiss projectile's soft sabot to be torn off.

[27] A memo from November 1863 specified that rifled guns should have 25 shells, 20 shrapnel (case shot), and 5 canister rounds in each ammunition chest.

In March 1865, a memo recommended that each chest carry 30 shells, 15 shrapnel, and 5 canister rounds for rifled guns of the horse artillery.

[20] The gun required a crew consisting of 1 sergeant, 2 corporals, and 6 gunners, while 6 drivers managed the horses.

Union General Quincy Adams Gillmore liked the Parrott rifles, noting that untrained artillery crews could easily learn how to operate them.

Confederate officer Edward Porter Alexander wanted to get rid of his 10-pounder Parrott rifles and replace them with M1841 24-pounder howitzers.

[35] At the Second Battle of Corinth on 3–4 October 1862, Battery H, 1st Missouri Light Artillery was armed with a mix of 10-pounder Parrott rifles and 24-pounder howitzers.