DaveH:

I Loc-Tite my blades into ferrule, so I have not noticed what you have described. However, on a couple of ferrules I use for practice that do not have the blades locked in, I have noticed that the blade channel on 1 or 2 ferrules did appear to have widened. Not much, but some. I scratched it off as caused by the repeated banging into targets and hard-foam deer targets.

I am going to measure the channels on the practice ferrules I have used.

I do not want to pay $70.00+ for heads!!!!!!!