I used 7 frames, I believe. I then timed each frame differently.
Remember that the torso faces us as the bow is drawn, and that the hand drawing the bow gets level to the eye, whilst the harm holding the bow is slightly below but parallel to it; you haven't been observant enough whilst watching/pausing the video I linked you to. You may also notice that the arm holding the bow is straight and at its full length during the whole cycle, which I moved up in three frames.