I got to ask...Why are you shooting 30-40 pounds? Are you young or old so the pull of a larger bow would be too much? Damaged? We have several hunters on here who have been badly hurt, Can you hunt with a crossbow in your state? That would give you a lot more penetration, and you could use just about any heads you choose. I also shoot a lighter bow when I use a compound. I use an Indian Stalker 45-55lbs and even at 55lbs, I seldom get a full pass through. With the crossbow, I get two holes, and a heavy blood trail. (because there is no arrow plugging the holes)
The only real difference between a good tracker and a bad tracker is observation. All the same data is present for both. The rest is understanding what you are seeing.