[Gear VR] Unable to hit 60 fps

I have a basic scene (FPS template BP) in two vartiations - One with disabled rendering of the view weapon model and the rest is as-is and the same scene, but with all unlit materials and removed sky sphere (it looks all black).

In both variants I get 58 fps and 17 ms using stat FPS console cmd. Using Unreal 4.10.4. Some people claim they have stable 60 fps in their UE4 games/prototypes on Gear VR.

Any idea what could be the issue? Thanks.