They are, which means you'll have a mighty hard time finding them.
I like the Wolverine 160, like the Grizzly they are very good steel and you can get them wicked sharp. The Wolverine is not as tough as the Grizzly, especially the lighter weights, but if you use the 160 and put a tanto tip on them they are plenty tough enough IMO. Being a single piece blade also means you can easily single bevel them if you want to.
I shot a small buck with a Wolverine 160 once, actually I pulled the shot and barely grazed him, and I mean barely. He walked off unharmed but the Wolverine was so sharp he still left small drops of blood for over 100 yards even though he was just fine.
I don't know where you can find Wolverines, the big auction site maybe. Our Tusker Aztecs are quite similar to them so we shoot those now (as well as many other heads).
Have a great season, Tim