The barrel configuration of a sporting shotgun can be more important than you imagine. Most guns were built along traditional lines with one barrel side by side with the other, and until the 1980s this was by far the most popular configuration. The rise in popularity of clay pigeon shooting, where this barrel configuration had been most popular, and a new generation of inexpensive guns of overseas manufacture changed the market forever. If you are going to be shooting mainly clay pigeons, then a modern over-and-under gun by a maker such as Browning or Beretta is likely to be your first choice. If, however, most of your shooting is going to be game shooting, then the traditional side-by-side shotgun still has strong advantages.