I have shot a number of deer with the large Deadheads. I do not remember them giving me a flight problem, I did have one not track through a deer straight, it looked like the head hit with blades horizontal. The deer was angled by the time the arrow hit. The path the arrow traveled in the deer was diverted. I imagine the spoon shape of the head did not help, but it left a huge gash, which made the long blood trailing job fairly easy. One of those hits when an 85 pound bow with a stuffed Microflite made a major difference. To get heads on straight I like to use a roller jig to check them. Spinning is a check as well, but the roller jig tells me which way a wobbly head needs to go.