BGfisher is on to the most important thing about muzzy broadheads, the blades can't come out of them. You can break the blades as you can with anyother broadhead, but they won't come out. We used to shoot broadheads into concrete walls. It is amazing to see a broadhead come apart. Muzzy broadheads never came apart, messed them up bad, but didn't come apart. Beltedmag I want you to know I have all the respect in the world for thunderhead, but I would not shoot them. I am old school, I shoot 130 muzzy 4 blade on a 2314 XX75 shaft at 26" 489grs. at 265f/s and I blow right through elk. And if you ask will they fly, yes. I tune for 80yds with my broadheads. The reason I put so much effort in is this, if they group at 80yds then 40yds is a chip shot. To push the point farther, I shot my ram at 55yds and there was no way you could lose that blood trail. If you have that kind of belief in thunderhead, don't change! And if you give muzzy a try, I would shoot 4 blade. And set them up to look like an X not a t. For me they shoot just like a dart.
Gselkhunter