I have been shooting Muzzys for years. I switched to 3 blades a few years ago because of a bad experience I had with what I surmised was the 4 blade. I had made a perfect shot on a whitetail buck at 15 yds. Watched the fletching disappear about 2" behind the shoulder about 1/3 the way up from the bottom. "perfect".
I gave him about 1/2 hour and started tracking. I jumped him after 100 yds and backed off. The next morning I recovered him 75 yds farther. After examination it seems that what happened and I am assuming was one of the blades caught the side of a rib, turned the shaft 90 degrees and came out just in front of the hind leg on the opposite side. My "perfect" shot only caught the left lung as it turned and passed thru the liver and intestines. Wierd huh?