Nautilus resistant to bullets, throwing people almost half a mile

Two and a half years ago, a group of pirates attacked us. They had a drifting yacht and they called out to us about starving families and sick children. The guns came out when they docked. They killed six people before we fought back. Three more before Nautilus showed up and they tried to shoot him, too. He’s just flesh and bone, but it’s really dense flesh. The bullets barely slowed him down. He punched one hard enough to crush his rib cage. Threw four of them almost half a mile out to sea, one after another.

Excerpt From Ex-Isle, pg 350
Peter Clines
https://books.apple.com/us/book/ex-isle/id989619017