What does O/U actually mean? Never shot a Shot Gun In my whole life. What are the advantages/disadvantages to having one?[/QUOTE
O/U stands for over/under, describing the barrel configuration. The main advantage over a side by side is the ability to install better sights, like the ventilated rib sight. Plus they look really cool.
Some of the most expensive shotguns in the world are O/Us and fetch in the 6 digits range. These Ruger O/Us are fantastic firearms. I once shot a beer can on the ground with one, knocked it in the air and hit it again with the second barrel, pure luck but I impressed the crowd.
Rick