M&P 10 Short Stroking

akrawc2 · Mar 22, 2013

I finally got to the range to fire the 10.. Before I went, I swapped the hand guard for a quad rail... Had to replace barrel nut and remove the gas block and reinstall... I was able to shoot 5 rounds.. brought the target in and put it out, shot 2 more, then the 3rd never went into the chamber... click (dry fire) check and no round... remove mag (Pmag) and reinstall charge handle and good, next round does not cycle...

I am leaning to gas block not aligned, but not sure since 7 rounds fired no problem and now won't cycle.. I even switched to a new pmag (20 round) loaded and first shot good, but did not chamber the 2nd round. I packed up and wanted to check it before I went more.

Few thinks to list:

I did not fire it from the factory new (I know, mistake)
I did not magazine 1 round to see if the bolt stayed open (I know, mistake number 2)

Just to move forward, I am looking of some input..

Thanks guys.

Aaron

jem450r · Mar 23, 2013

Are you using nato rounds? If i use reg 308 rounds i dont have problems but with nato rounds it doesnt feed correctly, thats my problem atleast. Just wondered if you were using nato or not. I think my problem is magazine related. Cheap metal asc i got i was skeptical right out of the box with

rojodiablo · Mar 23, 2013

Acrawc, you answered your own questions..........

cb4017 · Mar 23, 2013

Aaron, I would suspect the gas block first. Keep in mind the gas block does not seat all the way back against the shoulder on the barrel. If you remove the handguard cap the gas block needs to be off the shoulder the equivalent thickness, usually around .015" or so.

What ammo are you using? There is some **** stuff out there that won't work well in AR pattern guns.

akrawc2 · Mar 23, 2013

Thank you for the replies. As I kept thinking, I have the gas block messed up.. I did not leave the space foe the hand guard plate / mount. I am almost certain this is the issue..

Also using the attached picture ammo:

cb4017 · Mar 23, 2013

Sounds like you got it.

Don't count out the ammo. CBC has reports of not functioning in other AR pattern .308s on another forum.

$40?? is that for 20 rounds? Wow, I haven't bought ammo in a while.

akrawc2 · Mar 23, 2013

It was for 50 rounds ......

jem450r · Mar 23, 2013

Im having the same issues using the same ammo!!! Mine was 38.50 for 50 rds

akrawc2 · Mar 23, 2013

Did you do any mods or is it factory?

jem450r · Mar 23, 2013

akrawc2 said:
Did you do any mods or is it factory?

Factory, pmc ammo shoots great no problems... Have problems with nato rounds it seems, those are nato rounds you bought along with what i picked up and some other nato stuff i have.

cb4017 · Mar 23, 2013

What NATO ammo are you Gents using? I've run Lake City LC66 through my M&P 10 with no problems. I also have some WCC and TW that I'll try in the near future. Come to think of it 60s vintage LC Match runs fine too.

akrawc2 · Mar 23, 2013

Picture above shows the Box of ammo....

I adjusted the gas block today and blew air through and lined it up the best I could and have to say that from where I started and where I am now, I did not notice a significant difference in the sound of air.. BUT I know, range time will tell.. I am not optimistic, but will bring a different brand with me. Suck because I was stocking up on this before the 10 arrived, so I have 300 Rounds....

Maybe new Ornaments for the tree next year. Wife would love that!

jem450r · Mar 24, 2013

Im running the same ammo as pictured above. Along with some atomic ammo match grade 168 grain noslers, loaded in once fired military brass

akrawc2 · Mar 25, 2013

Put 50 rounds down the range today with not one issue. Shot 40 rounds of the above picture (started the same way with 5 shots, Bring in target sent out and 5 more rounds). Up the other 30 down with no issues. The shot some federal eagle

Looks like gas block alignment was off. I am very relieved.

akrawc2 · Mar 25, 2013

Also wanted to note the powder is pretty dirty

jem450r · Mar 25, 2013

Good to hear may have to mess with mine before i go back out.

BlueOvalBandit · Mar 25, 2013

akrawc2 said:
Also wanted to note the powder is pretty dirty

But cleaning is one of those great joys of owning a AR type rifle. For some hours of cleaning with crappy GI tools to get rifles "white glove clean" was a right of passage

Good to hear you got your problem sorted out. I have some CBC/Magtech ammo I bought for plinking with my Savage 10 and it gave a sticky bolt and wouldn't extract, had to use a rod. Apparently this is not unique with Savage rifles and CBC so I have 49 left. I'm going to give it another shot in my 308 Garand.

RR556308 · Apr 4, 2013

MP 10 short stroking

I have also bought an MP 10 and took it out to range right away with all factory hard-wear, did not change anything yet, SAME problem, almost every shot, round would eject, not pick up the next round, thought it was the 10rd MP10 mag I had, changed it out to magpul 20rd, same situation, I have been over every inch of the gun everythings good,(bolt,buffter ect..) changed ammo 3 times. Did you end up fixing your gun completely by moving the gas block? Doing the repairs is not the problem, Working on I gun I just bought IS. before I send it back just would like to know. thanks (magtech M80 was by far the worst)

akrawc2 · Apr 4, 2013

My gas block adjustment seemed to fix the problem... I also think throwing some rounds down range helped things loosen up a bit!

How many rounds have you put through so far?

RR556308 · Apr 5, 2013

About 120, most has been magtech cbc m80 ball ammo 2012 production. Everything I've shot has been 7.62x51 NATO so far, switching to AE 308d this weekend just to see what happens. Your now shooting the mag tech with no issues ? Been getting a lot of questions about the ammo but have no opinion yet Bc of the problems I'm haveing

M&P 10 Short Stroking

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