The funny thing in April, its not uncommon to see hard antlers, generally larger bucks, no antlers and ones with 4-6 inches of new growth all in the same group at the same time.
I'd have thougth in snowy regions mother nature would reserve the hard antlers longer, for defense? until closer to spring?
I've read that if there is a doe(s)that have not been bred yet and are still cycling, it will cause the bucks to keep producing testosterone and this keeps their antlers on their melons.
This is also why you sometimes see little spotted fawns in November.