The example that JM provided is typical of mid to high end European guns. I don't know of vintage American guns that have used this pattern. The 'squiggly pattern' above was used on many guns from Winchesters to Fox and Brownings later, with slight variations on depth and size of the 'squiggles'.
Another typical pattern on vintage American gun ribs is the "engine turned" pattern. This particular barrel set is an Ithaca with a flat topped rib. It can have different a look based on depth and whether concave or flat topped.
And this set has a concave rib top.
This is a LC Smith pattern, which is a series of little pyrimid shaped indentations.
http://www.pbase.com/roaniecowpony/image/49583640 If you tell us what kind of gun it is, I'm sure someone can provide what may have been factory original patterns.