Artillery Glossary

The horizontal bar connecting the two wheels of a gun carriage; upon this rests the trail or the cheeks of the carriage.

The journals of an axle upon which the wheels turn.

The entire axle, from arm to arm.

A reinforcing ring of iron or steel shrunk onto the breech area of a cannon to prevent the tube from bursting under the pressure of firing. Most prominently used in the Parrott and Brooke guns.

A tactical unit of artillery, typically consisting of six cannon in the Union Army and four in the Confederate Army, together with their crews, horses, limbers, caissons, and other equipment. Several batteries placed together in line formed a deadly defensive position.

A shelter dug into the side of a bank or constructed inside breastworks as small huts with heavy layers of dirt on top to protect from mortar shell fragments and solid shot. Troops and civilians alike became adept at constructing these during sieges.

The interior of a gun barrel; also the process of enlarging the interior of a gun barrel, as in re-boring smoothbores to accommodate new ammunition.

The rear, closed end of a gun barrel, opposite the muzzle. The most heavily stressed part of any cannon, hence the reinforcing band applied by Parrott and Brooke.

A two-wheeled vehicle carrying ammunition chests, used to transport artillery ammunition in the field. Each gun was assigned a limber and caisson.

The interior diameter of a gun barrel, usually measured in inches. Not to be confused with the "pounder" designation, which refers to the weight of the solid shot projectile fired by the weapon.

A thin metal container loaded with layers of lead or iron balls — essentially a giant shotgun shell for cannon. Devastating against infantry formations at close range (under 400 yards). Many proficient crews could fire two rounds of canister per minute, forcing advancing troops to seek cover repeatedly.

A hollow projectile filled with musket balls and a small bursting charge designed to scatter them over a wide area; also known as spherical case or shrapnel. Best used against infantry at ranges where canister became ineffective but solid shot was too concentrated.

In howitzers and mortars, the slightly smaller-diameter cylindrical or spherical cavity at the base of the bore that holds the powder charge. The lack of a chamber in the 1858 Columbiad design strengthened that weapon significantly.

A heavy iron artillery piece which could fire shot and shell at a high angle of elevation using a heavy powder charge. Usually classified as seacoast defense weapons and mounted in fortifications along rivers and waterways. Produced in 8-, 10-, 12-, 13-, 15-, and 20-inch models.

Naval artillery designed by Admiral John Dahlgren; distinguished by its distinctive "bottle shape" — heavier at the breech where pressures are greatest and tapering toward the muzzle. Iron Dahlgren smoothbores of 9- and 11-inch caliber were adopted in 1850-51; 15-inch versions replaced them in 1862.

The lateral deviation of a projectile from its line of fire, caused by the spin imparted by rifling. Rifled projectiles drift to the right (in standard right-hand rifling).

The angle at which a cannon barrel is raised above horizontal. Greater elevation increases range up to approximately 45 degrees, after which range decreases. The Model 1857 Napoleon had a range of 1,600 yards at five degrees elevation.

A mounting arrangement where cannon fire over the top of a parapet rather than through an embrasure, allowing a greater field of fire but exposing the gun crew.

Light, easily maneuverable cannon designed to accompany armies in the field. Distinguished from siege artillery (heavier, for fixed positions) and seacoast artillery (very heavy, for permanent fortifications). Lighter artillery pieces with muzzles ranging from 3.0 to 4.6 inches wide were the weapons of choice for field service.

A tactic first used by Confederate Artillery Major John Pelham, in which a gun battery would unlimber, fire, limber up, and quickly move to a new position — creating the impression of a much larger force. This tactic was refined and used in future wars as armies became more mobile.

A device to ignite the bursting charge of a shell at a predetermined time or upon impact. Time fuzes were set to burst a shell at a specific point downrange; percussion fuzes detonated on impact. The invention and refinement of reliable fuzes was one of the major technical challenges of Civil War ordnance.

An implement made of brass for setting wooden fuzes in the fuze-hole; the bottom is countersunk and cup-shaped to prevent slipping off the head of the fuze.

A three-pronged wrench used for setting fuze-plugs that are to be screwed into the shell.

A parapet built of gabions (cylindrical baskets filled with earth or stone) to provide protection for artillery positions.

The caliber of a gun; a device for measuring the bore diameter of a cannon to ensure it falls within acceptable tolerances.

A cluster of iron balls (usually nine) held together by a frame or bag and fired from a cannon; the balls separate upon leaving the muzzle. Less common than canister by the Civil War period; largely replaced by canister for anti-personnel use.

The spiral channels cut into the bore of a rifled barrel; together with the lands, they impart spin to the projectile.

A long-barreled, heavy artillery piece which fires solid shot at long range with a low degree of elevation using a large powder charge. Distinguished from a howitzer (shorter barrel, higher elevation) and a mortar (very short barrel, very high elevation).

An artillery piece with a shorter barrel than a gun; can fire projectiles at higher angles of elevation with smaller powder charges. Lighter and more maneuverable than guns. The Model 1841 12-pounder was the standard field howitzer of the Civil War; it could fire a shell over 1,000 yards with less than one pound of powder.

The most common projectile fired from the Model 1861 3-inch Ordnance Rifle. Designed by Benjamin and Andrew Hotchkiss as a three-piece shell: nose (containing the powder chamber), soft lead sabot band in the middle, and an iron forcing cup at the base which forced the sabot to expand and take the rifling upon firing.

A shell designed to start fires; filled with a flammable compound rather than (or in addition to) gunpowder. The "Swamp Angel" Parrott gun fired incendiary shells into Charleston, South Carolina in August 1863.

Projectile developed by General Charles T. James featuring a distinctive lead sabot system. Made in several patterns; the "tie-ring James" is the most recognizable variant. James also developed a system for converting smoothbore cannon to rifled pieces.

The raised ridges remaining in a rifled barrel between the grooves; the original bore diameter remaining after the rifling process. The lands bite into the sabot (or directly into the projectile in some designs) to impart spin.

A strong cord attached to the primer inserted in the vent of a cannon. Pulling the lanyard sharply caused the primer to fire the powder charge and discharge the weapon. One of the most dramatic moments in Civil War artillery — the cannonier stepping back, pulling taut, and firing.

A two-wheeled vehicle used to tow an artillery piece; carried an ammunition chest. The gun trail was attached to the limber hook to form a four-wheeled combination for transport. The caisson had its own limber and carried additional ammunition.

A stubby artillery piece which fires heavy projectiles in a high arc using small powder charges. Most effective when the target is above or below the line of sight. At night, the lighted fuzes of mortar shells could be tracked during flight. Classified as seacoast (10- and 13-inch iron), siege and garrison (8- and 10-inch iron), and field (Coehorn, 5.8-inch bronze).

Very light artillery pieces specifically designed to be quickly broken down and transported on horseback through rough terrain where wheeled vehicles could not pass.

The open, front end of a gun barrel from which the projectile exits. Most Civil War artillery was muzzle-loading — the charge and projectile were loaded from the front.

The most popular and dependable Civil War field gun — a 12-pounder smoothbore named after French Emperor Louis Napoleon. Range of 1,600 yards at five degrees elevation. Produced in bronze by the Union; in iron by the Confederacy when bronze became scarce. Sometimes classified as a gun-howitzer because of its shorter barrel and light weight.

The Model 1861 3-inch wrought iron rifle manufactured at the Phoenix Iron Company in Phoenixville, Pennsylvania. The only weapon officially known as the Ordnance gun. Distinguished by its smooth, uniform profile. Often (incorrectly) called a "Rodman" — Thomas Rodman had no involvement in its design or production.

Rifled artillery designed by Robert Parker Parrott, superintendent of the West Point Foundry. Distinguished by the iron reinforcing band shrunk around the breech. Produced in 10-, 20-, 30-, 100-, 200-, and 300-pounder sizes. Widely used by both armies; the largest Parrotts proved somewhat unreliable and prone to bursting.

In the Melton-Pawl classification system, the most significant level of projectile classification — based primarily on patent date. Designated by Roman numerals within each projectile family.

A fuze that detonates a shell upon impact rather than by a time delay. More reliable than time fuzes but potentially dangerous to handle.

A designation for artillery pieces based on the weight of the solid shot projectile fired — not the weight of the cannon itself. A "12-pounder" fires a 12-pound solid shot. Not to be confused with caliber measurements, which refer to bore diameter in inches.

A small device inserted in the vent of a cannon to ignite the main powder charge when a lanyard is pulled. The friction primer was most common in the Civil War — pulling the lanyard across a serrated wire created a spark.

Projectile pattern employing an expanding sabot attached to the shell base. Developed by John B. Read (patents 1856-57) and later associated with Robert Parrott; a post-war controversy arose over ownership of the patents.

A system of spiral lands and grooves cut into a gun barrel that imparts rotation to the projectile as it travels down the bore, dramatically improving accuracy and range over smoothbore weapons. The adoption of rifling on both small arms and artillery was the most significant military-technical development of the Civil War era.

A Columbiad produced using Lt. Thomas Rodman's special casting method, in which the gun is cooled from the inside out to prevent internal stresses. The resulting weapons were far stronger than conventionally cast guns. The largest Rodman gun, a 20-inch model, weighed 117,000 pounds and fired a 1,080-pound shot.

A carrier attached to a projectile to fill the gap between the projectile and the gun bore. In rifled cannon, the sabot (usually made of soft lead, copper, brass, or papier-mâché) expands upon firing to grip the rifling grooves and impart spin. In smoothbore cannon, wooden sabots centered the round shot and held the cartridge in place.

A cone-shaped projectile with ribs along the tapered base. The sabot was made of papier-mâché which was driven up the taper by the force of gas upon firing; the sabot then expanded and caught the rifling. Commonly fired from the 3-inch Ordnance Rifle.

Heavy, cumbersome weapons mounted in permanent fortifications along river banks and coastal waterways. Included the massive Rodman Columbiads and Dahlgren naval guns.

Heavy artillery pieces designed to be transported to siege lines and used against fortifications. Heavy enough to batter masonry but still theoretically mobile. Fort Pulaski (1862) demonstrated that rifled siege artillery could reduce masonry forts previously thought impregnable.

A gun with a smooth (unrifled) barrel interior. The dominant type of artillery at the war's outset; the smoothbore Napoleon remained one of the most effective field guns throughout the conflict despite the rise of rifled artillery.

A solid iron (or occasionally lead) ball or cylinder — the simplest artillery projectile. Effective against fortifications and enemy artillery. Solid shot at high velocity could skip across the ground like a stone across water, remaining dangerous for hundreds of yards after impact.

Holes or ears cast into the sides of mortar projectiles on either side of the fuze hole, used to center and handle the heavy spherical mortar shell for loading into the short tube.

The rear portion of a gun carriage that extends backward from the axle and rests on the ground when the gun is in battery; used to control recoil and adjust direction.

The primary cannon foundry of the Confederacy, located in Richmond, Virginia. The only working cannon foundry in the South at the start of the war; produced approximately 1,100 of the most common Confederate artillery pieces.

The metal cylinder forming the main body of a cannon — distinguished from the carriage (the wooden structure that carries it). Cannon tubes were cast in iron or bronze; Ordnance rifles were made from wrought iron.

The act of detaching the gun from its limber and placing it in firing position. A well-trained Union battery could unlimber, fire several rounds, limber up, and move to a new position in a matter of minutes — the basis of Pelham's "flying battery" tactics.

In the Melton-Pawl classification system, minor differences within a specific projectile pattern or sub-pattern — such as a wooden drive-in paper time fuze adapter versus a threaded paper time fuze adapter. The lowest level of classification.

A small hole drilled through the top of the cannon breech through which the primer is inserted to ignite the powder charge. After many firings, vents could widen due to erosion — a dangerous condition.

A hexagonal-cross-section elongated projectile designed to follow Sir Joseph Whitworth's hexagonal bore. Made an eerie whining sound during flight due to its shape. Prized by the Confederacy for extreme long-range accuracy.

The gap between a projectile and the bore of a smoothbore gun — necessary to allow loading, but reducing accuracy and power as gases escape around the projectile. Rifled weapons required tighter tolerances (less windage) through the use of expanding sabots, resulting in greater pressure and requiring stronger construction.

A corkscrew-shaped implement on a long pole used to remove unfired powder charges or fragments of the cartridge bag from the bore of a cannon after firing.