I just bought a brand new M&P 15-22 last week and shot abou 200 rounds with it (after fixing the ejection issue) with no problems. I got up to another 15 round mag and had one round just click when I pulled the trigger. The bolt was locked halfway back and it was stuck in place. I put it on safe and had to open it up real quick. I pulled the bolt and put it back in again. It then would move back and forth again. Then I placed the weapon on fire and a round immediately fired with no trigger pull or touch whatsoever. This happened again 5 rounds later. I put up the rifle and tried to call customer service. Of course they are closed until Monday. Does anyone have any ideas on this one?
(I was using Federals .22LR from the 550 Walmart bulk pack)

i would clear the chamber and start taking things apart. do you have the gun oiled? if not, reassemble and oil it along the way. IMO its better to have a little too much than too little.

Update: I took it out again today and fired 125 more through it trying to get it to happen again... nothing. It shot perfectly...

vitamind3: Yeah, I had it oiled and everything. I had dissassembled and reassembled (with more oil) on the range yesterday in between it happening. I was thinking it has to be something with the firing pin getting stuck back and then released by switching back to fire. Hopefully it is good now.
Thanks for the reply.

no problem. im guessing that you have already, but if you havnt, mmake sure you work some oil into the firing pin ***'y.

No way I'd take a chance on something like this and just hope that it doesn't happen again. I'd send that thing back to S&W immediatley!

I've handled all of the new line of .22 "AR's" over the last couple of weeks (S&W, Colt, SIG). I really want one, but am not overly impressed with any of them. I'm probably going to buy a Ruger SR-22 since it provides the same feel, is made of metal, and is based on a proven platform.

did you clean and lube the rifle before taking it out the first time? Most firearms ship with a rust preventative that needs to be cleaned out before use. The M&P15-22 is no exception.

.22s shoot dirty. Putting too much oil on the bolt area can result in gunking up the firing pin.