I have a question for the S&W MP 15 crowd. The barrel is marked 5.56 but i know that they are not always up to spec. How many of you have been shooting 5.56 through your S&W? Have there been any problems with the barrels? I have a good amount of 5.56 in the house and would like to get out soon and shoot it off. I know there are a good number of Smith owners out there, so I expect that the answers will vary, but lets hear them…
Should be GTG.
I have several AR’s (including Colts, Noveskes, Knights, a POF, and a LWRC) and two of them are S&W MP 15’s (an ORC and a FT). Both are chambered 5.56 and I shoot them on a regular basis at the range and they have both been through carbine courses without a hiccup. They tend to be my ‘go to’ and ‘beater’ rifles and will probably be my SHTF rifles should the need arise.
Not necessarily GTG. Barrels are only MPI batch tested. Only HPT batch tested as well. 1/9 twist also. If it starts popping primers, may need to ream chamber.
Just got an M&P15X a week ago, so I am no expert here. But I have put 350+ rounds through it, with half of that being 5.56. I have had no trouble at all. Honestly, I can’t imagine being any happier.
I’ve had my M&P 15A for about a year - put nothing but 5.56 through it with absolutley zero problems
Same experience; many thousands through my M&P, along with tens of thousands through many M&P-15’s my job issued, all in 5.56, and no problems.
No problem at all with many different S&W MP15’s and Federal XM193.
purchased my M&P15 last February and have shot over 1k rounds of WWB 55 grain 5.56 with no problems (no ftf, no jams, nothing). Also shot about 500 rounds of various 55 grain .223’s again with no problems so far FWIW, YMMV
I’ve shot a 1,000 rds of PP M193 through mine with nary a problem.
Scoby
Here here.
Lots of 193 without a problem. My barrel is also marked 1/7, and reliably handles 62-75 grain ammo.
Stock S&W? How did you end up with a 1/7 on yours? Wish i were that lucky.
Good question.
off topic, but I just picked up an M&P15X last week too! I’ve only put about 100 through it at an indoor range with the iron sights… glad to hear another happy owner…
Now to get schooled in optics… yikes
They will handle 5.56.
C4
I had to send mine back in for some work, and politely asked if they had any 1/7’s laying around BTW.
I got lucky. I don’t know where their 1/7’s go (VTAC or LE guns?), but I managed to snag one.
Two different M&Ps here, and no problems with any 5.56 or .223 ammo.
no issues. Prints 2 moa or better if I do my part. sitting at 2500 rounds since mid January. Hell of a fire ball with a compliant barrel though. Did a mixed mag test last weekend. shot mix of Wolf, some Bear stuff, American eagle tactical, Green tip, home loads, handful of mk262 and some 45 grain UMC.
Probably 90 random rounds. all functioned perfectly, but the group was huge 
Cleaned it this weekend and put another 250 rounds through it without any problems.
Optics is my next step also. Don’t know which way to go on that one.