Congratulations on successful 1st season. As eluded to your less than stellar penetration may be caused by many factors.
Would like hear more details on your shot that lead up to the less than penetration experience. Glad to see you asking the question now & hopefully putting in the time to improve your set up & tuning your arrow flight.
Question for the op. Under what circumstances do you wish to experience improved penetration?
Examples may include on perfect broadside shot with perfect arrow flight & perfect shot placement.
Or perfect arrow flight, less than perfect shot placement due to the reaction of the deer at the shot.
or you ofter the scenario.
What we may be getting at is while the broad head can make a difference. Clean, true arrow flight will make a difference as well. Perhaps more so!
If you are willing id recommend studying up on the benefits of arrow tuning, sharp cut on contact broad heads, high front of center weight distribution & momentum. The time is right to start digging deeper for next seasons path to success.