Back when Bear came out with the four blade Razorhead the average bow weight was 45#. Many people killed a lot of stuff using his four blade head with what we now consider to be lighter weight bows. I never bought it that two blades penetrated better than a well designed four or 3 blade. My wife shoots 45# and gets two hole in everything using 4 blade Phantoms and 3 blade Razorcaps. The key, I think, is perfectly flying well matched arrows and heads that are well made that will take and HOLD a razor edge.