Well guys I just wanted to give an update on these heads. They are awsome!!! Well at least for target pratice anyway!! I shot them friday evening and none, I mean none of them drifted on me, they all hit right dead on with the exception they are all at the bottom of the bullseye compared to my feild points, must be a tad bit heavier or a little more wind drag to slow them down, but still only about one and a half inch low!! Also as the tree rat said most mechs do not open until partway into the deer but these along with a few others have what I think is called the cam design and are forced to slide back as the cut on contact tip enters the skin and the blades are forced to be open before they enter the deer!! Most the mechs have a rear hinge and the blades have to fold back and thus not opening until part way into the deer, but not these!! and it works I measured all my POI's before I pulled them out and had between one and one eighth of and inch and one and one quarter of an inch slice in the foam!! Full deployment!! Now tonight I want to try DNK's paper test to make sure the are not premature opening up, but hey if they are I really don't care because they all flew right on the money!! Also another good thing is that as I did all this pratice I never broke a single blade!! Not one. But if i do its as easy as pie to replace, j ust unscrew the head and the blades slide in from the back!!