Four-Day Planet

Four Day Planet put me in mind of Heinlein's Juveniles. The protagonist is a 17-year-old reporter on his fathers newspaper. The newspaper angle kind of dates the book a little, even though on this far future planet the newspaper isn't actually printed but is telecast twice daily and its readers have teleprinters. The sole export on this planet is a product obtained from killing giant sea monsters, much like whaling. The culture is like the old west. Everyone carries sidearms, and sub-machine guns, sometimes called choppers, are readily available. Heavier military surplus weaponry, which seems to be WWII era, is also available. It's a reasonably entertaining read, but not particularly memorable.