Make sure your bow is properly tuned. If you don't have centershot and your arrows are a little tail left, right, high, low this will not allow a pass through.
If you have shot multiple animals and no pass through go back to the basics and make sure your bow is tuned properly. Unless you are hitting major bones like shoulder blade or spine the only reason I can see for not having pass throughs on deer is a untuned bow. Alot of people shoot mechnicals because they don't know how to tune their bow properly. no offense.
I would definitely switch to a COC head as mentioned above. Arrow weight is fine for deer. For elk I would switch to alot heavier arrow like FMJ and be shooting Atleast 425 grain total arrow weight. Good luck