M&P 10 Short Stroking

[Matrix187]

Same problem. Rounds won't eject completely. The gun is short stroking. Only Pmc 308 works out of prvi 308 168gr hp bt match, prvi 165 gr spbt 308, CBC 7.62, and portugese 7.62. I've shot 10 to 20 rounds of each of the aforementioned.

 

[RR556308]

Mp 10 short stroking fixed.

I took my MP 10 down to long competition saterday, I put 500 rounds down range without one problem, the gun needed to "break in". I have about 800 rounds through the gun and at 150 it started working perfect without changing anything, sAterday I shot the same magtech m80 I had trouble with 250rds with out one jam or short stroke. Ran about 4 different kinds of ball ammo then Switched over to match grade after that but this gun is very accurate at over 600 yards, I also used sig sauers tb-25 on the bolt and that seemed to help. So anyone with problems I would try to get up over 100 rounds before You get mad like I did , it's really a awsome gun.

 

[Blueapplepooh]

the gun needed to "break in".

I think people forget that this is a thing. Like cars, break your firearms in guys, as RR556308 said, this is an awesome rifle.

 

[Matrix187]

Ill try what you say, but a brand new gun usually does not short stroke every shot on most ammo types.

 

[Matrix187]

Its getting more reliable. Around 130 RDS now. Today I shot 30 and had just one FTE. Definitely grease the gun well.

 

[Blueapplepooh]

Definitely grease the gun well.

This is a must, even more so when brand spanking new. I've noticed this metal is thirsty. Soaks up the CLP nicely.

 

[Guns16823]

yeah i got mine out of the box last week....short stroke... put about 50 thru it cleaned it... another 50.... SS still tried to realign gas block SS on every other round tried diff ammo mag still does it...im at about 150 rounds

yes this is one thirsty gun.... drinks CLP

think im goin to grease..

i got another 50 to try then its goin back

 

[Matrix187]

So far CBC sucks, prvi 308 165 spbt works always, and portugese 7.62 works always, and Pmc 308 147 works always. The 'always' is after my first ~ 150 rds

 

[unknwn]

....Definitely grease the gun well....

Please elaborate.....
I haven't fired mine yet, and would appreciate any explanation of this " gun well " statement.
Since this M&P10 is my first foray into large bore auto-feeding guns (-or- any AR patterned guns at all) I have less experience than I'm comfortable with about the initial level of lubrication expected for reliable operation.

 

[Matrix187]

Strip and clean the gun before shooting for your first time. Grease the four rails on the BCG that contact the upper receiver. Also grease the bolt contacts, cam pin, and cam pin slot. I lightly grease the lugs even though its not needed.. Also one drop of clp on the gas rings. I use tw25b, and put just enough grease on to see a little white ( but not on the lugs, just a very little). Regarding the lower parts, a light coat of whatever oil or grease should help on the contacts. https://www.google.com/search?q=gre...AA&biw=768&bih=928#biv=i|13;d|mfMnf8Ycwju7qM:

 

[TXforFreedom]

I finally got mine to the range this past weekend. I have to say I was a bit worried with the reports of short stroking. Fortunately, I did not have any problems with it functioning properly. I was shooting winchester white box 7.62 x 51 147 gr.

I did clean my rifle before ever shooting it. I found no grease at all, just a lot of oil. The buffer tube/spring seemed completely dry and I did find one small metal shaving inside the trigger area. Not sure if this helped any, but I cycled the bolt about 50 times before taking it to the range.

 

[RR556308]

I would not send my rifle back I know it sounds crazy but 100 rounds is not broke in get above this 150 -200 , every round short stroked in my gun at first changed nothing and now it runs great, runs magtech m80 with NO problems at all , also working in the industry, sending guns back not the best idea right now, I can't speak for smith and wesson but MANY are so backed up you may not see your rifle for awhile.

 

[thatroolz]

Strip and clean the gun before shooting for your first time. Grease the four rails on the BCG that contact the upper receiver. Also grease the bolt contacts, cam pin, and cam pin slot. I lightly grease the lugs even though its not needed.. Also one drop of clp on the gas rings. I use tw25b, and put just enough grease on to see a little white ( but not on the lugs, just a very little). Regarding the lower parts, a light coat of whatever oil or grease should help on the contacts. https://www.google.com/search?q=gre...AA&biw=768&bih=928#biv=i|13;d|mfMnf8Ycwju7qM:

Thanks for the info on lub points. I am new to ARs and really have no idea where all of these points are, but I am sure I will find out. I ordered the M&P 10 from a local retailer on 4/5. How long did it take for you all to get yours if you had to order it?

 

[Matrix187]

Gunbroker. Took a week. Slightly unde msrp

 

[thatroolz]

That's reassuring, I guess. Maybe I wont have to wait till June to get it. *fingers crossed*

 

[10MMJeffro]

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.

actually, I'm not arguing, just giving an account of my experience this past weekend:

when I installed my LP gas block (troy), I, too thought it needed to be set out from the shoulder the equivalent of the thickness of the handguard cap...when I installed it this way, it short-stroked...once I set the gass block against the shoulder, I've yet to have another feeding problem (although I've only put an additional 40 rounds through it, but still, no failures.

an armorer friend of mine told me that the holes in the LP gas block are designed to "match up" to the hole in the barrel when the block is seated against the shoulder (they assume that if you're installing a LP gas block, there most likely will not be a handguard cap present), at least this very much seems to be the case with the Troy LP gas block

 

[MassDave]

see my http://smith-wessonforum.com/smith-wesson-m-p10-rifles/312533-home-home-range.html for details... but shot 80 rounds through mine yesterday with 3 types of ammo... the only failures to feed i had were the very first round, and 3 out of 20 of hornady steel match. all from 10 round asc mags. the 3 hornady failures the bolt just nicked the rim and scraped the side of the cartridge leaving an empty chamber.

 

[cnicks]

Same ammo, same results. I feel a little better after seeing these posts and I'm not the only one. 90 rounds no change, now I have lubed up good but not Happy with this type of performance. Don't like having to go back and slop on grease to get a rifle to work. Ammo too expensive to have to do this.

When back to the range,5-11-13, greased up and 60-70 rounds with NO problems. A check of the bolt before I started showed it had absorbed a lot of the oil I had applied. Left it alone and started firing and boy am I happy now.

 

[ole-cowboy]

actually, I'm not arguing, just giving an account of my experience this past weekend:

when I installed my LP gas block (troy), I, too thought it needed to be set out from the shoulder the equivalent of the thickness of the handguard cap...when I installed it this way, it short-stroked...once I set the gass block against the shoulder, I've yet to have another feeding problem (although I've only put an additional 40 rounds through it, but still, no failures.

an armorer friend of mine told me that the holes in the LP gas block are designed to "match up" to the hole in the barrel when the block is seated against the shoulder (they assume that if you're installing a LP gas block, there most likely will not be a handguard cap present), at least this very much seems to be the case with the Troy LP gas block

I am VERY intrigued by this claim, and would like some more information, I just put a troy lopro and a free-float on mine before i fired a round.

 

[ole-cowboy]

just stripped mine back down and noticed one of the two set screws on the troy low profile gas block is in direct line with the gas port.
I just spun the block upside down and peered in through the set screw hole the determined that a specially calibrated and certified razor blade is the perfect space required.
Spun the block back around drilled dimples for the set screws, loctited, and called it done