blazer
I've put about 400 rounds of blazer brass throught my M&P .40 without a glitch. I will second what Jason said, the alminum BLAZER seems to have a bit more kick to it, only 1 box fired for me. on a side note, wallyworld in EPPING NH had about 15 boxes of .40 and a good 50 boxes of .9mm as of Sunday and Rileys in Hooksett had a &^% load of .40 in there today, although I believe it was all federal.