I carry 40 Cal Zombie Max every day. I used to carry HST's, but I'm not impressed with the penetration power of the HST through different media. IE glass & sheet metal. You never know when you'll have to fire though a windshield or car door.
I got Z Max over CD for cost as well. Cheaper...and the shops here blow through it. Popular here too. And it's right on the box. "Just in case" how do we know there's no Zombie apocalypse coming soon? Be prepared. Lol