You'll need to call them. The carry a wide variety of ammo amd reloading components. But its best to call ahead if there's a specific loading you're after.
Hornady Zombie Max is available on their website so I am sure they have it or can get it for you. Right now HZM 185 GR 45.ACP is $20.20 for a box of 20 there... so the site says.
I don't remember seeing that specific kind of ammo there but that doesn't mean they don't have it. You could give them a call to see if they have it in stock and if they don't, they would most likely be able to order it and get it for you pretty quickly.
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