RE: Mechanicals heads?
The blades deploy rear-ward making them fold OUT wider than the given cutting diameter before protruding into the cavity and folding Back or settling into the 1.5 inch cut sustainded by energy.
Ill add by saying, look at a pic of a rage fully deployed, notice the blades are angle rear-ward, but when it first comes into contact with target, the blades cut into target at almost perfectly vertical state.