Another thing to consider is that you have made quartering away shots. While this is a great shot to take, there is a lot of deer to shoot thru, almost like shooting thru two broadside. Some more arrow/point weight should help if you can get it without sacrificing quality arrow flight, but I think you are doing just fine.
Regarding Mulberry River's post, the new Zwickey "No Mercy" heads are sharpened on both sides just like the other Zwickeys. Nice head, but narrow for my tastes.