I doubt PS4 will win by a "normal" margin, i believe will be much higer than June and even than March. Last year PS4 - XBO gap was over 250k, i think we will see probabily >150k gap this time.
XBO over 250k, PS4 over 400k.
And for October, PS4 will have a decent dropped, more than 250k but less than 300k, and XBO a nice jump... i believe One will be over 400k in October.
The 360 has sold 528k with Halo 3 in September 2007, so, i think is not crazy 400k for XBO with Halo 5.