Send it back to S&W and let them fix it!
I have found the S&W 1911s to be among the most reliable out of the box 1911s I've ever shot. Like a lot of people on this forum, when I hear about mixed-lot problems I immediately think ammo or magazines.
Before you contact S&W, I would suggest putting 50-100 rounds through the gun, log every malfunction and catagorize it...failure to eject, failure to feed, nose of bullet hit barrel hood, gun detonated and is presently in low earth orbit, etc. This really helps out on problem-solving. If I send a gun to a gunsmith and just say, "It won't shoot," they yell at me and demand more info. As Bill Laughridge so gently says, "You know how the damn things work! Tell me what's not working! Otherwise, how can you expect me to fix it, you idiot!" With most customers, he deltes the "you idiot" phraseology...
PS...Worsham, when you see me this weekend and buy me expensive designer beer, ask me why I recommended .44 Special revolvers for airline pilots!
Michael B