Well, according to the fundamentals in IPSC, which been the same since it was founded, the Speed, Accuracy and Power shall be 3 equal factors, and in pistol it seems to work, but as I understand it, the power factor in rifle is not equal, bcz some old history about the caliber 7.62x39. Someone that decided about the powerfactor levels for rifle wanted everything below .308 to be disqualified.
My opinion is to let the power be equal in rifle to, not only in pistol.
And about the .223 being an american round would maybe fit in USPSA but not in IPSC, as its an International issue, not domestic american issue.
Thats my opinion....