If I had 3 misfires out of 50 with hand loads, I wouldn't necessarily call that the fault of the handgun. I'd shoot at least 100 rounds of factory ammo before I made that judgement call.
And if it was still having misfires, I'd call S&W first and get it shipped backed to them for repair! They have an excellent customer service department and warranty repair.

"Allways speak the truth and you will never have to remember what you said before..." Sam Houston
Texans, "We say Grace, We Say Mam, If You Don't Like it, We Don't Give a Damn!"

~Molɔ̀ːn Labé Skýla~