Thanks for reaching out Dylan! The BlitzKing is a specialized small game hunting bullet, primarily because it commences terminal expansion/fragmentation the instant following penetration. In short, this bullet is designed to finish expanding before it reaches the depth where a whitetail's vital organs lie. I'm not going to say you couldn't kill a deer with a BlitzKing, but it's not advisable to try – wound channel's probably going to be too shallow.
I wish we had a perfect 223 Rem or 5.56x45 whitetail round in stock for you. The best I can recommend is the Atomic Heavyweight Hunting 223 Rem: luckygunner.com/223-rem-112-grain-rnsp-atomic-heavyweight-hunting-20-rounds. It will fairly limit your range, but it's the most effective option we have. If you'd prefer to look elsewhere then I'd highly recommend Winchester Deer Season XP or Barnes VOT-TX for deer hunting.