Idea just popped into my mind, why not use the 204 Ruger case (or 222 magnum) and open the Ruger case to 22 cal and use it in an extended 223AI chamber? Kind of like the 6mm BRX, but with a longer case. Just run the reamer in about another .090". Shoulder would be about .090" farther forward than a standard 223AI, for a bit more powder room. A 223AIX Just wondering if its been done, and if so, how did it work out?