| 3-inch ordnance rifle | |
|---|---|
 3-inch ordnance rifle, model 1861 | |
| Type | Rifled cannon |
| Place of origin | United States |
| Service history | |
| In service | 1860–1880s |
| Used by | United States, Confederate States |
| Wars | American Civil War |
| Production history | |
| Designer | John Griffen, Jr. Samuel J. Reeves U.S. Ordnance Dept. |
| Designed | 1854, 1862 |
| Manufacturer | Phoenix Iron Works (Phoenixville, Pennsylvania) |
| Unit cost | $330–$350 |
| Produced | 1860–1867 |
| No. built | 1,100 |
| Variants | 1854 (Griffen gun) |
| Specifications | |
| Mass | 820 lb (371.9 kg) |
| Length | 69 in (1.75 m) |
| Crew | 9 |
| Shell weight | 9.5 lb (4.3 kg) shell 1.0 lb (0.5 kg) charge |
| Caliber | 3.0 in (76 mm) |
| Barrels | 1 |
| Action | Muzzle loading |
| Carriage | 900 lb (408 kg) |
| Muzzle velocity | 1,215 ft/s (370 m/s) |
| Effective firing range | 1,830 yd (1,670 m) at 5° |
| Maximum firing range | 4,180 yd (3,820 m) at 16° |
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.