I have a 10" octagon .222 and .223's in 10, 14 and 21" lengths. I have shot the 10" .222 along side the 14" .223 and there was not difference in accuracy. Haven't done it recently, but from memory they were both very accurate.
Differences are greater availability of brass, particularly military for the .223. But the .222 has a longer case neck and depending what bullet you are shooting, that may have some value. Performance wise I don't think it is enough difference to matter in pistol barrels.