So my relatively new s&w m&p15 won't cycle the action when shooting. The hammer will reset but the bolt wont move at all. This happens with several different ammos, both winchester 223 and winchester/ federal 556.
First thing i did was clean and oil it. No difference.
Then I checked the bolt seals and they are in good shape. When standing the bolt up on it's extractor side it doesn't move, but will with light pressure.
I figured something must be wrong with the gas tube so I blew some carb cleaner through the gas port in the action (the nipple that interfaces with the gas key on the bolt). I expected it to be blocked but the cc ran out the barrel unobstructed.
I covered the gas port (in picture) with a piece of masking tape when shooting and gas came out enough to discolor the tape but not blow a hole in it. I know that's not super scientific but nothing wrong with more info.
I honestly can't think of anything it might be. Any info helps, thanks.
While this post is actually fine and within the community guidelines, we don't have the bandwidth to moderate it properly - and it really needs moderation. For that reason, I'm going to lock rather than remove the thread. Thank you for the high quality post.