The 3-inch ordnance rifle, model 1861 was a wrought iron muzzleloading rifled cannon that was adopted by the United States Army in 1861 and widely used in field artillery units during the American Civil War. It fired a 9.5 lb (4.3 kg) projectile to a distance of 1,830 yd (1,670 m) at an elevation of 5°. The 3-inch rifle was not as effective in firing canister shot as the heavier 12-pounder Napoleon, but it proved to be highly accurate at longer ranges when firing common shell or spherical case shot. There was only one reported case of a 3-inch ordnance rifle bursting in action. This was in stark contrast to the similarly-sized cast iron 10-pounder Parrott rifles which occasionally burst without warning, inflicting injury on the gun crews. The Confederate States of America lacked the technology to manufacture reliable copies of the 3-inch ordnance rifle. However, the Confederate States Army respected the weapons and employed those captured from Federal forces.

The 14-pounder James rifle or James rifled 6-pounder or 3.8-inch James rifle was a bronze muzzle-loading rifled cannon that was employed by the United States Army and the Confederate States Army during the American Civil War. It fired a 14 lb (6.4 kg) solid shot up to a distance of 1,530 yd (1,400 m) at 5° elevation. It could also fire canister shot and common shell. Shortly before the war broke out, the U.S. Army adopted a plan to convert M1841 6-pounder field guns from smoothbore to rifled artillery. Rifling the existing 6-pounders would both improve the gun's accuracy and increase the weight of the shell. There were two major types produced, both were bronze with a bore (caliber) of 3.8 in (97 mm) that would accommodate ammunition designed by Charles Tillinghast James. The first type looked exactly like an M1841 6-pounder field gun. The second type had a longer tube with a smooth exterior profile similar to a 3-inch Ordnance rifle. At first the rifles were quite accurate. However, it was discovered that the bronze rifling quickly wore out and accuracy declined. None of the rifles were manufactured after 1862, and many were withdrawn from service, though some artillery units employed the guns until the end of the war.