They've been having heat treatment problems with their spring supplier. It shows up more commonly is Shields because of how much stress such a small spring endures. Add in the fact that due to last in first out usage a defective spring can be in the parts bins for months before being installed and there's no way to see which individual springs have been effected until they fail. If they really have run out of recoil spring assemblies maybe the problem will get better, or not.