ElkNutz, thanks for sharing your issue. The opening on flight thing is something that others have found happening if the blades are not popped into the O ring completely or if they are bumped in the quiver or on a stalk. This most definitely would cause erratic flight. It is a side effect of having blades that require very little energy to open ensuring full expansion on entry. What I've done to prevent that is to use some small rubber bands in addition to the O ring. This way if the blade is bumped past the O ring the rubber band will keep the blade closed in flight. Some feel that you shouldn't have to do this, but I'd rather be safe than sorry.

As far as the penetration issue goes, you really can't expect a 2" cut expandable to have the same penetration as 1 1/8" cut replaceable blade broadheads. You have to give up some penetration to have a 2" cut. With that said there is no way to determine that if you hit that buck with your Muzzys that you would have gotten any more penetration. You may have just hit bone just right. There is just no way to tell.

I'm really sorry to hear you had such a bad experienc with them. My experience has been quite the opposite. I had one deer where I hit it high and a little back. The arrow passed completely through and stuck 6" in the ground. I caught the main artery running along the spine and thanks to the 2" cut also severed the spinal cord. Despite my bad shot the deer dropped in her tracks and bled out in 20 seconds. On the other deer I shot with them I was a hard quartering away shot that went in behind the last rib and came out in front of the shoulder providing a blood trail that went from the ground to 5' in the air on brush and trees all the way to the deer.

Overall, I've been very satisfied. Although I will say with how easily the blades deploy I would be hesitant to try a stalk with them. For stand hunting though, they are great IMHO.