not meaning to hijack this thread but maybe, hopefully, someone has the books or research that could list the different chamberings that could be tried on a given action size.

I.E. 12 ga.+ 500 or 577NE? NFB?
16ga.=450NE, 450#2 470
20ga.=450/400, ?
28ga.= I plan to do a 30/30 on one

This action is purely theoretical and any resemblence to fact is purely coincedental. It is just how I thought they might fit though I have no experience in such subjects. I was planning to use a 12 guage action for all my builds from 450/400 up to 500 or 577. I infer by the previous post that that may not be the idea way to do it. Does anyone has any information on what sizes of actions work with that chamberings to get the best balance and performance? If so PLEASE share!!!