Yeah, but I like the option of being able to use 3 1/2 shells and I already have the shotgun. I went to http://www.riflestock.com
and looked at some of their 10 round tubes. I called them and they said if you just opened up that piece on the barrel that holds the tube, or just removed it, you could use a longer tube from another model. THEY said all mossberg pump tubes are the same.
Mossberg didn't say that though, but the guy I talked to at Mossberg sounded like a jerk. Then just fashion up something to hold the tube to barrel. That should be easy.