My son called his section leader and platoon sergeant, both of whom insisted he had 72 hours to register (and they've both been through the process). His wife and I pointed out that this had changed upon issuance of the new policy, which requires registration before any firearm is brought onto the post.
He's not very communicative, but she is, and since she hasn't told us that he's in custody, I assume they managed to get things squared away.
![Wink ;-)](./images/smilies/icon_wink.gif)