I agree the planing is due to not having your bow propertly tuned. I shot muzzy about 3 years ago, but they were planing terrible out of my new bow, so I switched to mechanicals. I had my bow tuned by Crackers about 2 months ago. Just for the heck of it I shot a couple of my old muzzys and I couldn't believe the difference. They were shooting exactly like my field points. Now I'm torn on which broadhead to use this year. My muzzys or my spitfires.