That post is over 3 years old...

Hi All,

Knowing that this thread is old, and a lot of folks had the same problem moving forward, just wanted to comment. Had pretty much the same problem with mine that was returned to the factory and corrected. (mp15 short stroking thread)

Essentially, mine would fire, extract and eject, but not load a fresh cartridge. The bolt was not being blown back far enough. S&W replaced the whole bolt carrier assembly and sent it back within a month.

Their paperwork really didn't say much except that they replaced the bolt. I called S&W CS and pretty much pleasantly pushed the issue for my own knowledge. The rep I spoke to found in the factory records on my rifle, that the gas key screws had cracked and loosened, allowing a major gas leak.

The members here maintained that there was a big problem in the gas system which was verified. Being that there are no zombies at my door, I sent it back to S&W under their warranty which was honored. Bottom line was S&W paid for shipping both ways and repairing the rifle. Now, I could have bought a new BCG at my own cost and repaired it myself. BUT why should I pay out 80 to 150 for a bolt at my expense when the rifle is under warranty, and there is no civil unrest in my area at this time?

S&W CS will share any factory info on repairs if you ask and are persistent. Apparently S&W knows of a problem and will remedy it. in my case the bad screws have happened 1 in 600,000 times with S&W manufactured bolts. I noticed that, when inspected mine, that the screws were staked differently than the original bolt that came with the rifle.