Not much diff, really, between a 223 AI, 222 Mag and a 22-204 so far as burning powder and the results.
Something to beat dicks over...
I don't think Al ever had a 222 Mag. case.
One trip through an FL die, set up correctly, will give 110% positive headspace.
222 Mag, 222 Mag Ackley, and a 22-204 mock.