3-Inch Ordnance Rifle

Ft. Churchill State Park, Nevada, USA. From the adjacent interpretive sign:
"The 3 inch ordnance rifles arrived at Fort Churchill in October 1864. These were the first type of rifled cannons produced in large numbers for the US Army. Although these cannons were still loaded through the muzzle, [the] improvements of rifling and using a projectile instead of a cannonball provided greater accuracy and longer range than other field guns of that time."
Ft. Churchill was built in the early 1860s to (a) intimidate Confederate sympathizers; and (b) intimidate the local Paiutes. It succeeded on both counts. The fort was abandoned by 1870 and sold for scrap. The timbers were salvaged, but the rest of the buildings, made of adobe, fell into ruin. The well-defined "ruins" visible now are actually 1930s restorations--the original buildings are now just heaps of mud.
Inset shows a caisson displayed inside the museum.