Andy and Greg, >>>Well, I think it takes a physicist to really explain it but I believe that the stuff that goes out backwards is caused by the material, early on in the event, not being able to go forwards (too much apple ahead) and the area or direction of least resistance for stuff the projectile pushes out of the way is backwards. Eventually the front rips open and then material is pushed and also carried forwards by the bullet.<<<<< Actually, I think it's based on the pressure waves the precede the bullet. You may remember the classic image of the bullet captured in mid flight, an old high speed black and white. It shows sound and pressure waves leading back and away from the lead point of the bullet. Our air has mass is the reason for this. The front impact on the apple is a physical representation of this affect. The pressure waves take the general form of whatever projectile that's creating them and it is these waves that hit the apple first. The apple's density exceeds the air density and therefore the material is pushed out and away rather than into the apple. I'm no physicist, just read a lot. Take care, Gregory david Stempel FIREFRAMEi m a g i n g
