What Rob is talking about is since the blades open from the front, to the rear, the blades need to enter the animal before they open. Since the blades aren't deployed as they enter, as they are with the Snyper, the entrance hole is smaller. BUT.....it's moot point, IMO. They only need to enter the animal 1" before they are fully deployed, so by the time the blades get to the lungs and heart of the deer, you're at maximum cutting diameter.

The ones I don't like are such as the old Punchcutters. The tip of the head had to be depressed, which is what opens the blades. JUNK! If that tip gets clogged, or whatever, before the blades open, or for some reason the tip returns to it's before shot position while still in the deer, the blades will retract back inside the head. At that point, you may as well be shooting a field point at them.