It's about the weight of the barrels. If they are heavy they best be short. If they are light, then they can be long. Almost all barrels for the American market are too heavy. Especially on SxS's and O/U's. Some pumps and autoloaders are better than good. The Brits, Spanish and Germans know how to make long and lean SxS's and O/U's. The Italians also if they want to.
Long and lean point better than short and fat.
