Cody, I noticed that on page 1 of this thread you said the unit you are interested in had two mountain Howitzers, two 6-pounder James guns, and eventually two 10-pounder Parrott rifles.
The Mt Howitzers are essentially shorter, light versions of the 12-pdr field howitzer (the gun tube itself weighs only 220 lbs.). Originally, they were broken down and packed on the backs of mules. Some still were in the Civil War, but experience had led to the development and deployment of a wider, more stable "prairie" gun carriage and a prairie caisson in the 1850s. That was the more common Civil War mounting. In essence, these became scaled down versions of the standard no. 1 field carriages. (While the prairie gun carriage was drawn by a two-horse team, the first prairie caisson was drawn by a horse or mule between two shafts; later a limber was added and that pulled the caisson body in the usual manner by a two-horse team.) However, they continued the use of multiple long, narrow, eight-round ammunition boxes in lieu of field ammunition chests.
These were highly maneuverable, very effective weapons. They could go about anywhere a cavalryman could go and fired the same shell and spherical case (shrapnel) round as the 12-pdr Napoleon and 12-pdr field howitzer, but fired an even more deadly canister round -- one containing 148 .69 caliber lead musket balls vs. the 27 inch-and-a half cast iron balls of the Napoleon or 48 one-inch cast iron balls of the field howitzer. Due to the reduced powder charge used, their range was shorter -- about 250 yds for canister, 800 yds for case and 1000 yds for shell. Rowell's Yankee Artillerymen describes their use by Lilley's 18th Indiana Independent Battery (the artillery for Wilder's famous "Lightning Brigade"). That battery also had 3" Ordnance rifles which are functionally equivalent in operation to the 10-pdr Parrott (though stronger and about 100 lbs. lighter).
The James rifle was a rifled version of the 6-pdr bronze gun. Due to their elongated shape, the James rounds weighed around 12-14 lbs. rather than 6 lbs. They worked well except that the heavy, rifled rounds too quickly wore out the rifling of these comparatively soft bronze guns. However, 40 were still in use with the Army of the Cumberland at Chickamauga in late September 1863.
One interesting fact about the M. 1860 10-pdr Parrott, named after its inventor Robert Parker Parrott, that might be of use: the original model (which I believe was the first rifled artillery adopted into federal service) had a 2.9 " bore. This became a problem after the Army also adopted the 3" Ordnance rifle. The 3" rounds could jam in the 10-pdr Parrott tube. Later Parrotts were manufactured in 3" size (3" Parrott). Some earlier ones may have been re-bored to 3" but it was important for the gunner and crew of a true 10-pdr (2.9") Parrott to pay attention and not load the wrong size ammunition. In addition, Parrotts were made of cast iron with a wrought-iron reinforcing band and had a reputation for bursting. This was rare in 10-pdrs, but did happen (may have been the result of loading the wrong ammunition), and was a greater risk in the 30-pdr and 100+-pdr Parrotts.