Well a 223 AI picks up 2 grains of case capacity, at 36 grains this would be 5 more than factory 223.
223 wssm is 53 grains of capacity, which is pretty much equal to a 243 case. No wonder the 223 wssm failed, a 243 necked down is already a short action caliber without any issues of feeding the short fat cases. Barrel burners though...