Agreed, Doug--drillings with two shotgun barrels above a rifle barrel tend to be balanced like a double shotgun should be for wing shooting. I suspect the ones that are the other way around (double rifle over shotgun barrel) are rare partly because they aren't good for wingshooting.
I'll just have to experiment with the 2400 on a skeet range with spreader loads to see if I can hit anything, without the scope, and with the scope switched to 1X. My only other experiment along these lines is with my Savage 24, which has a Weaver V3 also. A full choke .410 is a hard gun to hit with, scope or no scope, tho.
May have to stick to "terrestrial" targets like coyotes and turkeys and cottontails in the end, but I'll try it out on clays anyway, and let you know what happens. Not until first week of Jan, the first chance for me to get away to shoot.