Tree Climber, years ago when I first looked into hunting turkeys with a bow, I looked into the washer behind the head as an arrow arrester. I was told back then to make sure to use some sort of arrow arrester to stop the arrow (o-ring, rubber band, washer, or store bought units).

I choose the Zwicky Scropios becasue they slide on the shaft to cause lesss dammage to the meat and do not effect the flight of the arrow. Dnk, the scropios do impact alot of shock into the bird (complete KE from the arrow). I once shot a Tom at 7 yards and the arrow hit, moved the bird 2 yards on impact. To see the bird move sideways on impact was quite the sight. Also the head usually sticks out a good little distance past the bird. Another god thing abouut the spitfire's is that after they exit and the as the arrow slows, the free motion of the blades will allow them to close so the sharp edges are not waiting to cut someone.