Well, not the sub-forum name I hinted at, but close enough.
Feel free to start threads relating to calibers based upon the 450b parent case. They do not have to be only known commercial offerings. They can include wildcat calibers as well, either in existence, in process, planned or "would like to see".
Realistically, this is a place, hopefully not only in history, to keep the 30 Remington AR alive, it is also a place to dream and speculate.