Silly Sunflower Seed Question

I planted some giant sunflower seeds in my yard this year. I also had one large sunflower volunteer, probably from a birdfeeder.

Well, they all grew very tall, as promised, and had spectacular flower heads. The thing is, when I checked some of the seeds, I found that they were empty! I peeled back the hull and found no seed or germ of any kind, just an empty striped hull.

I this a usual problem with the large sunflowers? Were they not pollenated? I saw plenty of honey bees, carpenter bees, and even a couple of hummingbirds flying around them. But almost every seed is a "dud".

My multi-headed sunflowers delivered seeds as always, and the goldfinch are already going to work on them.

I think it's possible you have a sterile hybrid or one which is self-incompatible. The latter would have to bloom at the same time as some other compatible sunflower within range of the same pollinators.

Huh. I'll be! What's the point of growing a giant sunflower if not to get lots of seeds from it? Is there something I should be looking for on the packaging that would indicate that a particular variety will or won't have viable seeds. Can anyone suggest some "winners"?

Also found it interesting that the birds and squirrels aren't even wasting their time on the flower heads. It's as if they can tell (or smell) that the seed shells are empty.