Good morning Stan,

It would have been great but Browning never made the sub gauges in anything longer than 28" barrels.
30" tubes on a sub gauge Superposed would have been the Bees Knees.

Plenty of 20 gauges were made "Lightning" and many weighed 6 pounds and a couple ounces.
They removed extra wood from the buttstock and milled a lot of weight out of the receiver.
The 28's and 410 barrels were fit to the same frame but were heavier (read barrel weight) so I"m guessing never as light as the lightest 20's.
Mine should be 6 1/2 to 6 3/4 lbs.

Merry Christmas and a happy and healthy New Year to you and your family.

Credit where credit is due,
Skeettx thinks subgauge sets are fun to shoot, buzz's comment is puzzling crazy