This might be a good time to discuss artillery. I won't spend much time on it personally, I will just cut and paste from two one line sources with links, but it's pretty important backgrond material. These two links do a good job, so without further discussion or contemplation:
http://en.wikipedia.org/wiki/Field_artille...rican_Civil_War
Smoothbores
Smoothbore artillery refers to weapons that are not rifled. 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. As such, many smoothbore weapons were still in use and production even at the end of the war. Smoothbore field artillery of the day fit into two role-based categories: guns and howitzers. 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. Additionally, the artillery was often identified by the year of design in the Ordnance department references.
The smoothbore artillery was also categorized by the bore dimensions, based on the rough weight of the solid shot projectile fired from the weapon. For instance a 12-pounder field gun fired a 12 pound solid shot projectile from its 4.62-inch (117 mm) diameter bore. It was practice, dating back to the 18th century, to mix gun and howitzers into batteries. Pre-war allocations called for 6-pounder field guns matched with 12-pounder howitzers, 9 and 12-pounder field guns matched with 24-pounder howitzers. 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.
Guns
Smoothbore guns were designed to fire solid shot projectiles at high velocity, over low trajectories at targets in the open, although shot and canister were acceptable for use. The barrels of the guns were longer than corresponding howitzers, and called for higher powder charges to achieve the desired performance. Field guns were produced in 6-pounder (3.67 inch bore), 9-pounder (4.2 inch bore), and 12-pounder (4.62 inch bore) versions. Although some older iron weapons were pressed into service, and the Confederacy produced some new iron field guns, most of those used on the battlefields were of bronze construction.
The 6-pounder field gun was well represented by bronze Models of 1835, 1838, 1839, and 1841 early in the war. Even a few older iron Model of 1819 weapons were pressed into service. Several hundred were used by the armies of both sides in 1861. But in practice the limited payload of the projectile was seen as a shortcoming of this weapon. From mid-war on, few 6-pounders saw action in the main field armies.
The larger 9- and 12-pounders were less well represented. While the 9-pounder was still listed on Ordnance and Artillery manuals in 1861, very few were ever produced after the War of 1812 and only scant references exist to Civil War use of the weapons. The 12-pounder field gun appeared in a series of models mirroring the 6-pounder, but in far less numbers. At least one Federal battery, the 13th Indiana, took the 12-pounder field gun into service early in the war. The major shortcoming of these heavy field guns was mobility, as they required eight-horse teams as opposed to the six-horse teams of the lighter guns. A small quantity of 12-pounder field guns were rifled early in the war, but these were more experimental weapons, and no field service is recorded.[5]
By far the most popular of the smoothbore cannon was the 12-pounder Model of 1857, Light, commonly called "Napoleon". 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. It is sometimes called, confusingly, a "gun-howitzer" (because it possessed characteristics of both gun and howitzer) and is discussed in more detail separately below.
Howitzers
Howitzers were short-barreled guns that were optimized for firing explosive shells in a high trajectory, but also for spherical case shot and canister, over a shorter range than the guns. While field use alluded to firing at targets consisting of enemy forces arrayed in the open, howitzers were considered the weapon of choice if the opposing forces were concealed behind terrain features or fortifications. Howitzers used lower powder charges than guns of corresponding caliber. Field howitzer calibers used in the Civil War were 12-pounder (4.62 inch bore), 24-pounder (5.82 inch bore), and 32-pounder (6.41 inch bore). Most of the howitzers used in the war were bronze, with notable exceptions of some of Confederate manufacture.
Coupled to the 6-pounder field gun in allocations of the pre-war Army, the 12-pounder field howitzer was represented by Models of 1838 and 1841. With a light weight and respectable projectile payload, the 12-pounder was only cycled out of the main field army inventories as production and availability of the 12-pounder "Napoleon" rose, and would see action in the Confederate armies up to the very end.
As with the corresponding heavy field guns, the heavier howitzers were available in limited quantities early in the war. Both Federal and Confederate contracts list examples of 24-pounders delivered during the war, and surviving examples exist of imported Austrian types of this caliber used by the Confederates. These 24-pounder howitzers found use in the "reserve" batteries of the respective armies, but were gradually replaced over time with heavy rifled guns. Both the 24- and 32-pounders were more widely used in fixed fortifications, but at least one of the later large weapons was with the 1st Connecticut Artillery as late as 1864.
12-pounder Napoleon
The twelve-pound cannon "Napoleon" was the most popular smoothbore cannon used during the war. It was named after Napoleon III of France and was widely admired because of its safety, reliability, and killing power, especially at close range. It did not reach America until 1857. It was the last cast bronze gun used by an American army. The Federal version of the Napoleon can be recognized by the flared front end of the barrel, called the muzzle swell. Confederate Napoleons were produced in at least six variations, most of which had straight muzzles, but at least eight catalogued survivors of 133 identified have muzzle swells. Additionally, four iron Confederate Napoleons produced by Tredegar Iron Works in Richmond have been identified, of an estimated 125 cast.
Rifled guns
Rifling adds spiral grooves along the inside of the gun barrel for the purpose of spinning the shell or shot and enacting gyroscopic force that increases the accuracy of the gun by preventing the shell from rotating along axes other than the axis parallel to the gun barrel. Adding rifling to a gun tube made it more difficult and expensive to manufacture and increased the length of the tube, but it increased the range and accuracy of the piece. While most of the rifled guns in the Civil War were muzzle-loaded, a small number of breech-loaded guns were used.
3-inch ordnance rifle
The 3-inch (76 mm) ordnance rifle was the most widely used rifled gun during the war. Invented by John Griffen, it was extremely durable, with the barrel made of wrought iron, primarily produced by the Phoenix Iron Company of Phoenixville, Pennsylvania. There are few cases on record of the tube fracturing or bursting, a problem that plagued other rifles made of brittle cast iron. The rifle had exceptional accuracy. During the Battle of Atlanta, a Confederate gunner was quoted: "The Yankee three-inch (76 mm) rifle was a dead shot at any distance under a mile. They could hit the end of a flour barrel more often than miss, unless the gunner got rattled."
Parrott rifles
The Parrott rifle, invented by Robert Parker Parrott, was manufactured in different sizes, from 10-pounders up to the rare 300-pounder. The 10- and 20-pounder versions were used by both armies in the field. The smaller size was much more prevalent; it came in two bore sizes: 2.9 inch and 3.0-inch (76 mm). Confederate forces used both bore sizes during the war, which added to the complication of supplying the appropriate ammunition to its batteries. Until 1864, Union batteries used only the 2.9-inch (74 mm). The M1863, with a 3-inch (76 mm) bore, had firing characteristics similar to the earlier model; it can be recognized by its straight barrel, without muzzle-swell.
Parrotts were manufactured with a combination of cast iron and wrought iron. The cast iron improved the accuracy of the gun but was brittle enough to suffer fractures. On the Parrott, a large wrought iron reinforcing band was overlaid on the breech. Although accurate, the Parrott had a poor reputation for safety, and they were shunned by many artillerymen. (At the end of 1862, Henry J. Hunt attempted to get the Parrott eliminated from the Army of the Potomac's inventory.) The 20-pounder was the largest field gun used during the war, with the barrel alone weighing over 1,800 pounds (800 kg).
Whitworth
The Whitworth, designed by Joseph Whitworth and manufactured in England, was a rare gun during the war, but was an interesting precursor to modern artillery in that it was loaded from the breech and had exceptional accuracy over great distance. An engineering magazine wrote in 1864 that, "At 1,600 yards (1,500 m) the Whitworth gun fired 10 shots with a lateral deviation of only 5 inches." This degree of accuracy made it effective in counter-battery fire, used almost as the equivalent of a sharpshooter's rifle, and also for firing over bodies of water. It was not popular as an anti-infantry weapon. It had a caliber of 2.75 inches (70 mm). The bore was hexagonal in cross-section, and the projectile was a long bolt that twisted to conform to the rifling. It is said that the bolts made a very distinctive eerie sound when fired, which could be distinguished from other projectiles.
*Ammunition*
Ammunition came in wide varieties, designed to attack specific targets. A typical Union artillery battery (armed with six 12-pounder Napoleons) carried the following ammunition going into battle: 288 shot, 96 shells, 288 spherical cases, and 96 canisters.
Shot (or bolt)
Shot was a solid projectile that included no explosive charge. For a smoothbore, the projectile was a round "cannonball". For a rifled gun, the projectile was referred to as a bolt and had a cylindrical or spherical shape. In both cases, the projectile was used to impart kinetic energy for a battering effect, particularly effective for the destruction of enemy guns, limbers and caissons, and wagons. It was also effective for mowing down columns of infantry and cavalry and had psychological effects against its targets. Despite its effectiveness, many artillerymen were reluctant to use solid shot, preferring the explosive types of ordnance. With solid projectiles, accuracy was the paramount consideration, and they also caused more tube wear than their explosive counterparts.
Shell
Shells included an explosive charge and were designed to burst into a number of irregular fragments in the midst of enemy infantry or artillery. For smoothbores, the projectile was referred to as "spherical shell". Shells were more effective against troops behind obstacles or earthworks, and they were good for destroying wooden buildings by setting them on fire. A primary weakness of shell was that it typically produced only a few large fragments, with fragment count increasing with caliber of the shell.
Spherical shell used time fuses, while rifled shell could be detonated on impact by percussion fuses. Fuse reliability was a concern; and shell that buried itself into the earth before detonating had little anti-personnel effectiveness.
Case (or shrapnel)
Case (or "spherical case" for smoothbores) were anti-personnel projectiles carrying a smaller burst charge than shell, but designed to be more effective against exposed troops. While shell produced only a few large fragments, case was loaded with lead or iron balls and was designed to burst above and before the enemy line, showering down many more small but destructive projectiles on the enemy. The effect was analogous to a weaker version of canister. With case the lethality of the balls and fragments came from the velocity of the bursting projectile itself—the small burst charge only fragmented the case and dispersed the shrapnel. The spherical case used in a 12-pounder Napoleon contained 78 balls. The name shrapnel derives from its inventor, Henry Shrapnel.
The primary limitations to case effectiveness came in judging the range, setting the fuse accordingly, and the reliability and variability of the fuse itself.
Canister
Canister shot was the deadliest type of ammunition, consisting of a thin metal container loaded with layers of lead or iron balls packed in sawdust. Upon exiting the muzzle, the container disintegrated, and the balls fanned out as the equivalent of a shotgun blast. The effective range of canister was only 400 yards (370 m), but within that range dozens of enemy infantrymen could be mowed down. Even more devastating was "double canister", generally used only in dire circumstances, where two containers of balls were fired simultaneously.
Pictures of some examples can be viewed by clicking on the link.
Looking forward to it.His arduous overland trip from the west coast at the beginning of the war has a romantic flair to it. Always thought it would have made a great movie.
Oh, by the way... BL, when you cover Donelson, were you considering a bio on Forrest? Great cavalry commander, played a big role in the west and later, but .. very controvesial guy, being the first head of the KKK. If not, I can do it when you start on the river battles. I'm almost done with Shiloh, which has turned into a small book. 
