If it were the M&P with the problem, wouldn't other ammunition companies also be issuing the same warning. Why just Wolf?
Does the M&P 15 different models come with the same BCG? Wolf is not saying problems with the Sport or OR , etc.... model, but all M&P 15's.
We on the forum are thinking the problem is possibly the BCG, but for Wolf to make a blanket statement without documentation for all to see is speculation and innuendo.