That explains it. He's probably around 270 fps tops even with the Matthews. It's an issue of the bow's speed and how stable the arrow is to begin with. If the arrow is close to instability from the start and you add wind it's going to not fly well.

After a few years out of the game I was hoping that Muzzys would be just fine. However, a few articles had meapprehensive if that was still the case. Both said that 280 fps was about the max for a fixed blade broadhead. In a fenced yard with no wind they did fly good and I thought I was in the clear. Then, I decided to shoot them at 30 yds in the wind and they broke loose on me. i just ordered some Wac'emtriton XL 125's to try. I've read some good articles on them and they should be good.