Sub-sonic .30s

[Builder45]

Does anybody have any experience shooting or hunting w/ calibers such as the .300 whisper or 30-221. I am trying to decide whether to get a wildcat or just use the .308 win for a suppressed rifle project.

I want a caliber that will effectively kill deer sized game but be able to do it sub-sonic. I am going to build this rifle strictly for a suppressor. Any replies are greatly appreciated. Thank you.