Problems with a Smith & Wesson M&P 15 PSX piston rifle.

don304 · #1 04-12-2010, 04:23 PM

It looks like Smith & Wesson has an issue with the M&P 15 PSX. I ran into problems the first time I fired this model at the range. Each trip to the rifle the Piston Block comes loose. The set screw and locking pin both back-out after 30 rounds. I contacted Smith & Wesson’s service department and received assurance that the problem would be resolved. I returned the rifle to Smith & Wesson last week with an assurance that the rifle would be repaired and returned in short order. Today was informed by the Service Department that they had received the Rifle and should know something in two to four weeks. This is not the service I expected to from Smith and Wesson.

mag318 · #2 04-19-2010, 05:46 PM

I have an M&P15ps with the polymer handguards and no problem at all with the block coming loose. I'm sure they will fix yours but agree that's a long turn around time. These things are a brand new model for them and perhaps there's a few bugs with their first piston system design. My block is held in with one pin and after 200 rounds still tight. Good luck and keep us posted on yours.

don304 · #3 04-21-2010, 11:01 PM

Mag18 – thank you for the reply…the gas block on my rifle is the same – it is attached with a pin and set screw. Overall my experience with the service department turned out positive. I am convinced that Smith and Wesson manufactures a quality product and will stand behind it. After receiving and checking my rifle – they replaced the “upper” assembly and returned the rifle. The gas block remained tight after 100 rounds at the range today. Perhaps it was an early production problem.

mag318 · #4 04-23-2010, 03:34 PM

Don, I think S&Ws first piston system AR is a good one. I chose it over the Ruger and others because of the light weight mainly. I was really impressed by how clean the M&P was after a range session. These piston ARs seem to be the wave of the future even though a lot of people think there is no need for them. I understand that in the upcoming M4 trials the Army has specified they want a piston system if they do in fact do an upgrade. I'm sure our rifles will be in those trial, so it will be interesting to see the results.
The only mods I made to mine was the addition of a Magpul CRT stock and I had Armalite install one of their tactical two stage triggers. For sights I mounted an AGOG TA11, I'm quite happy with the setup.