DT: The AMO draw length is defined very well. From the throat of the grip to the inside of the nock of the arrow at full draw, plus 1 3/4". If they can measure brace height (a static measurement), the draw length is just the same measurement but done at full draw - plus 1 3/4".

About 8-10 fps for every inch of incorrectly stated draw length. There's your actual 310 when you thought you were getting 320.