What happens to the arrow's point of impact as you put more pressure on the bow with the heel of your hand. In other words when the lower limb comes more into play. I'm finding I have the odd high flier and can't determine the cause.

JW

You are right, heel pressure is the most common cause. Some bows are touchier than others. My ACS is really touchy but if I'm consistant with hand placement it's very consistant

I should have mentioned that I have nocking points above and below the nock.

JW

I have a Hill style bow which is (more or less) designed to have you "heal" the bow.

If your having heal push issues. Hot melt a tack to the lower grip. That cures you of that quick!!

go hit the blank/ blind bail and work it out and solidify your hand placement.  

If you normally use a higher grip, with the webbing of the hand and base of thumb in the throat of the grip taking the pressure, then "heeling" the grip as you shoot will cause you to shoot high.  A high grip on the bow can prevent this, and though I shoot with a "high" grip, I can't stand a high grip on a bow, as I find it too restrictive, too "tight."  There is nothing wrong with shooting with a low, or heel pressure, grip, as long as you do it all the time.  I am super sensitive to grip design; if the grip doesn't feel right, I can't shoot that bow well.