Briley has not made 410 tubes with 3" chambers for a number of years. I think they will still do that on a special order, additional cost basis, but as one who shoots a majority of 410 ammo over the other gauges, I would question the need for the 3" shell. With normal sized shot used for clay targets, there is simply no advantage over the better patterning 2 1/2" shell.
The only advantage of the long hull is a few more large pellets. If you need 4's or 5's, you likely need a larger gauge gun.
Even if you are going to harvest squirrel or rabbit, the little shell has plenty of pattern with larger shot out to near 30 yards with a good choke.