I've had two crack on one of the top threads similar to jds44's. They were on a rifle that was abused though, spending a lot of time on a tractor and atv...it took a beating and had nothing to do with recoil. I can say one pair showed no change of zero but didn't test the other.
I still have several rifles that wear TLW's, but generally go with DNZ's if I'm buying now.
