So, you want to extend the .223 pill to beyond the normal ranges. Speak to an EXPERIENCED re-loader.
I don't do it myself, as I don't have the desire. But the thing that i have learned from those who do. Is that what you want, and what is SAFE are not usually one and the same.

As my father might say. This is where common sense comes into play. Just because you might want to do something, doesn't mean you should.