In my recent endeavors to try new things, Im going to shoot some Rage 2 blades this year....now for those who use them, do you replace the blades after a kill??? How hard is it to do this?? I have read several reviews that say that when you try to replace the blades, the allen screw that holds them in gets stripped or cross threaded or something b/c of the shot head.... several guys say they only get one kill out of a head....that is too expensive for me!! what's the deal....??