Uncharted 4 can it be the best selling in the series.

[Boutros]

The Uncharted trilogy sold over 21m as of June 2015 but we have it at like 18m at the same point in time.

So I think Uncharted 3 is well past 8m but it was heavily bundled.

Assuming Uncharted 4 gets a similar treatment I think it can sell over 10m copies fairly easily.