I'm with the other posts, there is a distinct sound you should hear if you hit the animal correctly (?thwack? or ?Poof?- pop of lungs), and the sound is different if you hit the animal poorly or bone as stated. However, you should be able to see the arrow hit the animal. I only use brightly colored fletchings and nocks. Using both will help you watch the arrow flight and find the arrow easier. I can always watch my arrow hit the animal and my actual arrow speed is over 300 fps so no excuses that your bow is too fast. This won?t help now, but try to practice doing this when you target shoot, without flinching or closing your eyes of course. I?ve found this is not only more accurate for me but trying this may pay out in the future for you too.
Secondly, spend more time looking for the arrow since this will answer your question. Carefully mark the spot you and the animal were standing in when you shot the arrow. I?d retrace the path repeatedly and beyond since the arrow is usually always nearby on a near straight line path. Spend the majority of your time walking this straight line and looking for sign of a buried arrow, under pine needles, in yucca cactus, etc. Only much later, then start to expand your search beyond and then side to side. I have watched the arrow exit the animal at a different angle (changed course during pass through), but this is not very common and in my experience it is not very significant.
If he was hit well (pass through) he?ll leave blood everywhere, the arrow will usually be easy to find and we wouldn?t be having this discussion. You may have hit him bad or completely missed. Get on your hands and knees and track the deer?s steps after waiting for at least 20-30 minutes, looking for tiny drops of blood. Track the animal meticulously and look for blood not only on the ground but on small bushes about the height of the deer?s chest that the deer inevitably brushed up against while running off. The blood may not be dripping much and may be only on the hide if he?s not hit well, which he will rub onto brush as he runs through thick cover. If the animal took off bolting he may not leave much blood for the first 100 yards till he slows down, especially if hit poorly. My guess is if you really can?t find the arrow or blood, then (1) the animal is hit poorly and initially ran off with the arrow; (2) the arrow deflected off something, which you probably missed completely. (1) Requires much more work and time, and as stated I think you almost owe it to the animal to look harder. If (2) then look harder for the arrow as this is the only thing you can do. Don?t get me wrong it sounds like you have given a very good effort and you probably already do many of these simple things.
Maybe get some new fresh eyes to help you next time if you can. Good luck!
