Lands And Grooves - Fort Missoula, Montana

You may be educated in interesting terminology when you show your slightly odd photos to select people at the office ("select" being those who do not have small children and/or a puppy, so as to avoid, er, generous reciprocal photo sharing of images that actually include people in the photos - Egad! What are they thinking!).

Per my ex-military colleague and FireArmsID.com, the curving pattern visible in today's photos (and in James Bond movie intro footage) consists of  "...lands & grooves. The lands are the raised areas between two grooves. A rifling pattern of eight grooves with also have eight lands. Firearms can be manufactured with any number of lands and grooves in their barrels.  They can also spiral either left or right.  A few of the more common rifling patterns are 4/right, 5/right, 6/right, 6/left, 8/right, and 16/right."

This view is from the back of a Civil War model 1861 3" ordnance rifle, manufactured 1861, serial #15, muzzle-loader, which was converted to a breech-loading salute gun.
Hayes and Amalia Otoupalik donated it from their collection, in memory of his twin brother, Josef Otoupalik. Head on over to Fort Missoula to take a look for yourself and read the rest of this item's history. The weather is still lovely for brisk meandering.