I purchased my M&P40 just after I graduated AIT in the US ARMY. Since then, I have put well over 10K rounds through it. Factory and handloaded ammo. In the amount of rounds I have put through it, id say maybe a full magazine has had problems. (note: it was cheap wolf ammo. The issue was with the casings, not the firearm.) with its weight being amazingly distributed , the high capacity magazine, ease of use, and amazing price, i give the M&P40 5 stars all the way around. Either slow fire from prone, or rapid fire from standing, my M&P is always right on target, and always thirsty for more. I actually carry it as my side arm while hunting! Thank you Smith and Wesson. Amazing job.