I took my new M&P Shield 9mm to the range today. Put 100 rounds through it. Zero issues with 70 or so rounds of hardball, but tried some older +P factory JHP I had laying around (Remington 115gr and Black Hills 115gr). Anyway, I had 2 failures. Both times the spent case didn't fully eject and was still completely "inside"/slide jammed open (i.e. not really "stovepiped"), so the next round never chambered.
Any thoughts? Maybe something wrong with the gun ejecting spent cases?
I also put 50 rounds thru a Glock 23, no problems/no failures, and that was a dirty rental gun! I don't think I was limp wristing with the Shield. I did strip, clean and lubricate the new Shield before I brought it to the range.