Calculating (using my old algebra skills, that my children say they will never use), I came up with about a 2.8 oz load...
Good grief, we are shooting a bird ON THE GROUND with a shotgun... Yes, I'd like to shoot them with a superior load, but I would not go to an RPG if they let us...
Personally, I'd like to see a TSS/Hevi-shot load in the 14-15 g/cc range with a few more pellets of larger size (making larger holes). 1 5/8 oz payload #7's with plenty of pellets, and with that density I would expect a pass-through at 40 yards. But alas, I feel the ammunition companies are catering to what the average hunter thinks is better, than with what would actually work better in many cases. Sell what sells...