Guys, you prove MY point. Pushing a cut to tip through leather IS easier....you are at the extreme slow end of the scale (less than 1fps...HOW does THAT relate to the real world?). As speed increases, it gets eaier and easier to go through the leather. When shooting an animal, you have to go through something much thiker than a peice of leather. The entire head is surrounded by matterial. The HUGE surface area of the cut to tip heads causes more drag than the replaceable blade heads (or even a mech head...BLASPHAMY....or is it?).
like cutting through a block of cheese, the less surface area, the easier it is to cut. hence cheese cutters are VERY dull, but have VERY little surface area (peice of wire).
Try to cut grass with a razor moving at 1 fps...then open up the weedwhacker with it' s super dull mono line...a bit easier...even though the razor has a MUCH higher KE (It' s weight, plus the weight of your arm/body).
None of this REALLY matters, as long as you put the head where it belongs. Indians killed deer with jagged rocks tied to bent sticks for cripes sake!