I have put around 7k rounds through my M&P 40. About 300 of these is Winchester Ranger 165 grain. I have had about 5 jams using WWB and none with the ranger ammo. Today I noticed that my brass was ejecting straight back and after 5 shots the gun jammed. I cleared the jam and continued shooting. After the last round, the magazine dropped and the slide cycled forward. Hmmmmm....... I have read similar issues on this forum. What were the outcomes? Also of note, the magazine I was using was my "carry" magazine, meaning I successfully put 100+ rounds through it in the past without a failure and that it has has the same 15 rounds in it for about 6 months.