Makes me glad I never got a Shield in .40.
Never had a problem with my Kahr all steel .40's, but obviously they are not Shields.
I have used American Eagle and Winchester White Box, with about 150 rnds of Federal HST thrown in.
I wonder if the many trainers who run high round count classes have seen any kind of a trend.
If anyone has seen this they would seem to be the most likely to note it.