Do you give them free choice oyster shell or mix it in? They are getting more calcium than the store bought eggs. Nothing wrong with it though, as far as I know.
Mine are a tad bit harder than store bought as well which I think is awesome! I don't give them oyster shell either!
I had a hen lay her egg on a shelf in the coop - it fell off from about 7ft up and didn't break. She keeps laying them up there, and about 50% of the time they do get a crack. But I still think its pretty amazing
When my son and I were doing our comparisons, we were actually suprised to see that our eggs shells were Ever so slightly Thinner than the store bought, however, they were much harder to crack. We couldn't figure it out at first. Then we noticed that it was the inner Lining of the shell that was much more tough and thick than that of the store bought egg. I think I could almost peel the outter shell off of the membrane without it breaking on our eggs. I suspect this is because our hens are happy and not living under stressed conditions like those in the mass egg production line of work. It's a good sign to have strong eggs!! Even if the shell is a little thinner, it is probably more dense and thus stronger that way too.
