GP100man, a couple of thoughts. 2-bladed prop or rotor. Veral Smith addresses 'lop sided' bullets in his book. I do not necessarily agree with everything Veral touts, but if anything spinning is balanced, well, it's balanced. But here's another thought. The barrel is also a swaging device. Most often we load a bullet of larger diameter than groove. I'm currently working on a batch of bullets that are beagled base only to add a bit of girth to the drive bands. GC fits snugger, but still goes on easily. I can now pass the bullet through a size die .001 larger than before, and it comes out round with the GC the same diameter as the drive bands which a barely kissed by the die. They shoot extremely well. So, if you are going to do 'lop sided' bullets, they need to be symetrical. Sometimes it works, and sometimes it doesn't.