We have been blunting Bobs cones and CLE's etc for years. Its not rocket science. You are trying to keep the water attached to the gearcase more easily. We don't blunt ours nearly as much as the ones in the photo, more like the size of your index finger. You could do a speedmaster as well, but their aspect ratio is already good at keeping water adhered pretty well. Also closing off one of the water inlets decreases aeration of the water going by on one side and allows for a slightly better bite. Some do port, some starboard. Smoothing the rough edge by the inlet helps as well , as does filling the drain hole on CLE and 200 cases and using rear drain carriers or just removing the putty etc when filling and replacing it afterwards. Skeg work helps , as does torque tab work.
steve is right!!!!! blunting a nose on a sporty is as easy as it gets...
the theory, or fact is that is creaest a air pocket around the side of the case. less friction = more speed. the same theory of a 747 jet!!!!!!!!!!!
sharp point = friction lower speed. doesnt handle as well.
perfect blunt speed goes up. handleing is better, less friction.
to blunt = blow out, not enough water hitting the back of the case. the "air pocket" is to big. some people will add a blow out ring to compensate. may work , may not.
the happy medium is great. my sporty went up 2 mph. handleing was better as well. i like a worked sporty on a ally. number one case of choice on a ss for around boating.JMO
roy