Some of the 12ga boxlocks--not a lot--came with 30" barrels. I expect some people who are looking for a gun to shoot in sxs sporting clays competition might choose one of those (likely with choke tubes installed) as their competition gun. People looking for a game gun, however, would find that such a gun handles like the proverbial pig on a shovel.
I have a BSS boxlock Sporter with 30" barrels, and a Miroku/Daly 500 with 30" barrels. Both are M/F and make pretty decent late season dove guns when the birds are high and fast. Also nice to shoot in high winds. The 500 with its PG/splinter is trimmer than the BSS, but both swing quite well. The BSS Sporter 30" also looks about as good as any basic boxlock ever needs to look. The long barrels were retrofitted to both guns, which came with 28s.
