HELP! trigger will not pull back!?

[kipwshields]

UPDATE:  got it!! Thank you all for your help. I am a fist time owner of an AR... the pin directly above the trigger came loose!? It was causing my trigger to freeze. It also had this green build up on there I will clean. Thank you so much for your knowledge! I appreciate it

I bought my 556 sport and put about 25 rounds from a 40 round clip. It was going fine then nothing. Removed the clip checked the chamber everything looked good. Put clip in loaded it and everything went fine... my trigger will not move! It won't pull back at all. Went through 4 rounds this way. Put my stock clip in and same thing. The trigger does not pull. I tried to put it back and forth on safe. Still nothing. And suggestions? I am new to the AR world's so any ideas will help. I don't want to have to send it back to the factory please help!!

 

[ChattanoogaPhil]

Could be a lot of things that a simple inspection would reveal. My first guess is a primer.

 

[sgtsandman]

Look for something in your trigger group. It sounds like something got in there and is binding up the works. It could be a popped primer, a sliver of brass from a shell casing...

 

[JaPes]

1. Separate your upper from your lower.

2. Turn your lower upside down.

3. Gently tap the lower to dislodge any loose debris.

4. Using a flashlight, look for any debris that could impede trigger function.

5. Manually cock the hammer. If the hammer will cock and hold, move to the next step.

6. With the hammer cocked, engage and disengage the safety. If the safety will engage and disengage, move to the next step.

7. Safety off, hammer cocked, put your hand over the hammer to catch it. Press the trigger. Do not let the hammer impact the aluminum lower.

At which step are you having issues? That will give us some clue as to what's going on.

 

[kipwshields]

I got it!! Thank you all for your help. I am a fist time owner of an AR... the pin directly above the trigger came loose!? It was causing my trigger to freeze. It also had this green build up on there I will clean. Thank you so much for your knowledge! I appreciate it

 

[JaPes]

I got it!! Thank you all for your help. I am a fist time owner of an AR... the pin directly above the trigger came loose!? It was causing my trigger to freeze. It also had this green build up on there I will clean. Thank you so much for your knowledge! I appreciate it

The trigger pivot pin wlaked loose from the lower receiver? Assuming you're running a stock combat thrigger, the trigger pin has a notch in it. That notch should be inserted so that it is on the ejection port side of the lower. One of the hammer pin legs will seat into that notch to keep the pin from walking out. The guy who made this video yaps on and on forever. Fast forward to 6:26 in the video for an illustration.

If after confirming that your trigger group is installed correctly you still have issues with the pin walking, then a set of KNS Precision anti-walk pins is in order.

Magento Commerce

If your pin is consistently walking and you bought your M&P brand new, call S&W. That trigger pin hole may be out of spec. That would be a warranty claim.

 

[speedyquad]

i was going to suggest the pin walked. i almost put those anti-walk pins on my ar build just because.