S&W M&P10 - From Stock to Not

[Jwryan84]

If you do not mind me asking what warranty claim did you make? I do not have an M&P 10, but I have heard many good things about them. It seems the common complaint has been that they are unreliable with overseas ammo. I am interested to hear what problems you are having. Thanks.

I'd like to know also( just picked one up.

 

[henschman]

I'm not using overseas ammo -- just Lake City 147 grain 7.62x51. It won't lock back on empty, and has frequent "bolt over" fail to feed/fail to eject malfs, which are signs of undergassing.

 

[mightymouse]

I would think if anything shortening the barrel would make it even more undergassed. Less dwell time = less gas pressure at the carrier key.

That's my understanding as well. Less dwell time = shorter duration gas pulse = undergassed.

 

[Jwryan84]

DPMS types are know for mag issues also. I have an Armilite/Noveske AR-10 and have never had a malfunction of any type. Guess I'll see with mine, but can always make the hole bigger.

 

[henschman]

FYI, I got my M&P 10 to run reliably on 7.62 this weekend. Drilling the gas port out to 5/64" did the trick. That was the smallest bit I had that wouldn't fit in the port. It now runs great on several different types of surplus 7.62. Now that I can actually somewhat trust this thing, I can finally justify sinking some more money into it... I will be following in your footsteps with a free float handguard over low-pro gas block setup, among other things.

 

[Gabriel42]

FYI, I got my M&P 10 to run reliably on 7.62 this weekend. Drilling the gas port out to 5/32 did the trick. That was the smallest bit I had that wouldn't fit in the port. It now runs great on several different types of surplus 7.62. Now that I can actually somewhat trust this thing, I can finally justify sinking some more money into it... I will be following in your footsteps with a free float handguard over low-pro gas block setup, among other things.

Fantastic to hear that. Are you planning to suppress it? I haven't made it back out to the range but I hope to change that this week.

Wow... 5/32 = .15625. I believe that mine is at .088

 

[Jwryan84]

It should run dirty......

 

[henschman]

Haha, I meant 5/64". Yeah, 5/32" would be a little big!

Here is what mine looks like now. Yeah, I am pretty sure I will go down the suppressor route one of these days soon.

 

[Gabriel42]

Very nice. Still have some tweaking to do. Really want a Vortex Razor HD 1-6x to replace the Viper PST 4-16x. Just seems like too much magnification for what it is when suppressed.

Your rail reminds me that I need to cancel my backordered .308 VTAC rail. Surprised it hasn't shipped already as it was supposed to be 4-5 weeks behind the Alpha rail.

 

[henschman]

Thanks.

Yeah, I have mine set up in more like a battle rifle/hog hunting configuration. The 1-4x I have on there is great for that type of shooting... head-sized targets from point blank out to 300 yards, torso-sized targets out to 600 yards, and hog-sized targets out to 300 or so, but optimized for the more likely closer distances. The rifle only weighs 9.4 lbs. unloaded with that setup, so it will carry nicely for a .308. I will run mine in some of the upcoming Run 'n Guns and see how she does. Yeah, I pulled that Troy handguard off another .308 I built a couple years ago. The M&P ended up being everything I was going for with that build only better, so the other got taken apart and will be used for another project (6.5 CM build). I wouldn't have gone with the Troy again if I didn't already have it sitting around... I would go for the Midwest SS Gen 2. I have them on two of my 5.56s, and like them a lot. Also I'm not a big fan of Troy after they hired that anti-gun former Chicago police chief and the JBT sniper who was at Ruby Ridge and stuck up for Lon Horiuchi afterwards.

Gabriel, from your pics, it looks like your rifle has a heavier barrel than the standard lightweight M&P one like mine has. Is that part of the MA configuration? It looks well-suited to what you are wanting your rifle to be... a little more precision-oriented, and a suppressor host. A 1-6x sounds great. You also might be into something like a 2.5-10x if you want to go a little lighter/faster, but still with a decent top end for precision. Anyway, keep us posted on your progress... I hope to see it (and you) at Pawnee on Jan. 17!