There is no bow (no matter what configuration the limb are) that will not make an alarmed deer react. There are however times when deer do not react at all. I have shot over the back of deer with a slug gun with no reaction at all. I have also had deer bolt at the sound of my arrow being pulled back over my rest. One things for sure if you have an alert/alarmed deer in your sights you had better aim a bit on the low side no matter how fast your bow is unless the deer is looking at you. If the deer is looking at you it will see the movement of the limbs. The difference between the speed of sound and the speed of light(deer seeing the limbs move) is enough to allow the deer to possibly "jump" the string. Believe it or not there is solid math involved here between the deer's reaction time and the speed of sound/light and the speed of the arrow. A deer's reaction time makes an arrow almost seem slow