I am not a firearms expert, but I own and use an M&P 9mm full size. The first time my wife fired a handgun was with this gun, and she had one failure to eject properly (limp wrist most likely). My friend had one failure to fire shooting the gun when I had purchased some ultra-cheap ammo (I will let you guess which brand). I have not had any issues with the weapon other than those 2 in over 1000 rounds at the range, qualifying for CHL, etc. Here is the ammo I regularly use without any problems for reference: Hornady Critical Defense JHP 124gr, Georgia Arms FMJ 124gr, Blazer brass and aluminum case 115gr, WWB, Remington FMJ 115gr, Selliot & Bellot FMJ 115gr, Federal Hydrashok JHP 124 gr. Great gun, very accurate, easy to shoot and easy to clean.