I'm not talking about 18" HD models...those are plentiful. I'm talking about the 21"-24" vent rib barrels that are so nice to have on a hunting shotgun. I know that the manufacturers make them, but gun stores on the West Coast seem to sedom (if ever) stock them. From what I have heard, these barrel lengths are a dime a dozen in the Eastern United States. Is this true? And if so, why?