Hey everyone, I am relatively new to this forum and would like some feedback on some of the mods I plan on making. Just received my MP10 yesterday and plan on using it for hunting and range time.

Magpul UBR collasible stock (will I need the S&W spacer?)
Magpul Miad Gen 1.1
Magpul AFG2

Troy TRX 13.8 plus low profile gas block (.75)
Troy Battle Sight Front Tritium HK Folding
Troy Battle Sight Rear Tritium Di-Optic Aperture Folding
Not sure on the bipod, any ideas?

Thoughts?

Has anyone put a UBR stock ont their MP10? If so did you need the spacer or any additional parts? Called SW CS today and they said I would need the spacer which has not been released yet (according to several other posts it has been released). Any input would be greatly appreciated.

I DO NOT HAVE FIRST HAND KNOWLEDGE OF THE UBR

now I have that out of the way, from images of the UBR, the buffer tubed portion is fixed so I would expect you would need the spacer.

Easy way to find out is to install the stock and slide the BCG into the tube with buffer and without the spring and make sure the BCG does not contact the receiver before everything bottoms out

FYI....

Hi,
The Magpul UBR stock will NOT work with the M&P10. This is a custom ar15.com stock that has it's own proprietary receiver extension. This is NOT compatible with the M&P10. Although it "may" function, it is highly doubtful.
Your best bet is to use a standard Rifle Length stock (While using a rifle length receiver extension, the existing buffer and spring, and the spacer mentioned in above comments from S&W.) or using a mil-spec collapsible stock and using the existing receiver extension and buffer/spring.

Thanks, S&W

Measure the inside depth of your S&W buffer tube compare to the depth of the magpul tube is there a difference? If the UBR is shorter you may have to make it up in the lower by not screwing the UBR tube into the lower as far! take out your BCM! and put it in the S&W tube with the buffer and not the spring ,make a mark on the BCM with a pencil note that mark when you slide the same into the UBR tube screw the UBR tube into the lower and then the buffer and BCM and note that mark ON THE BCM! Look closely. understand you are making up that difference by not screwing in the tube all the way that is how you are matching the depth! If you have to screw the S&W tube in and compare the mark and referance on each one until you know were your at. take your time ! Also blue lock tight is a must ! and you'll be able to remove later! Put a unloaded mag in it charge the rifle make sure it locks back and moves to battery! make sure your BC lock's in the barrel extension fully! I checked the action with 308 WIN. snap caps before proceeding to the range, and the results are worth it. this worked with my F93 Ergo they insisted would work on an S&W MP10 And was off by 1/8th " You also may not be able to use the stock buffer and spring as the detent spring and buffer retainer will be of no use I solved this with a JP Rifles silent captured spring! if you still go with the original buffer and spring and detent you will have to pull back on the charging handle every time you open the upper ! Yea it all sounds expensive and involved but the results are awesome! Remember take your time and you'll get it! Reverse this procedure if you experience the opposite! (by cutting down tube) had that issue on a long ago build.

Can't speak to the stock and bi-pod with the configuration you want to put it on, but would WARN you about TROY INDUSTRIES.
I have TROY magazines and several sets of TROY folding sights in both the M-4 and HK designs. Those sights are very well built. But that's about all that is positive that I can say. Just purchased their 45-deg offsets and made the mistake of trying to install the front mount on a (very fine) SLR adjustable gas block and it was way too tight.
Long story but to make it a short story; The [new] sights have three parts, sight block, picatinny mount and a single countersunk screw to put them together. The countersink was off center and tweeked the mount on the rear sight and the front mount had to be relieved with a file to fit the SLR block. No small choir as the anodize is hard as the hubs of hell. Why did I work so hard to get them to fit? Because I needed them now (that's why I ordered them-dammit!). AND, a customer representative told me "there are no parts available for sale as they are produced on a one-for-one basis". Now that's &%$# GREAT! Should have known better as I was told the same thing about a year ago when wanting to replace the DOA aperture I personally hate (old eyes). The new picatinny mount is a one piece pinch affair that would hard pressed to not bend or break if dropped on it.. $239 MSRP is too much for me for ANYTHING that the manufacturer will not supply parts for.
If'n I were you I'd go with someone like SLR Rifleworks instead of supporting TROY. Still not convinced.. google, 'troy and vicky weaver' and then tell me how you feel about that? Wish I'd know that tidbit from the get-go..

TROY INDUSTRIES WILL NEVER GET ANOTHER DIME FROM ME

Still curious? Google['troy and vicki weaver']

The RE of the UBR is not proprietary, it's actually made for the entry length stock. The entry length RE is carbine length and uses the carbine length buffer and a carbine length spring. That means an even shorter length buffer is needed as the MP-10 carrier is longer than the standard AR carrier

I have used the UBR stock on my MP10, with a JP enterprises captured recoil buffer setup. go that route, you will have no problems. this setup combined with the Syrac Ordnance adjustable gas block makes this rifle shoot like a dream.

Off topic but what handguard are you running?

Brentster, I am a novice with the AR platform and trying to get my new-to-me M&P10 to work with a UBR that has already been installed. Since the bolt carrier group won't lock back and the UBR seems to be commonly considered a cause for this, can I just purchase and replace some items in the UBR and get this combination working?

Is it possible for you to point me to (a) specific URLs/item numbers at JP Enterprise so I can purchase and replace? I've spent some time looking at their selection guide, but couldn't really determine what item(s) I needed.

Thanks in advance for your help.

Hi there,

I run a UBR stock on my M&P 10 and use the JP Enterprises captured recoil spring assembly. It's been flawless on my rifle. Unfortunately, the exact model from JP Enterprises that I used has been discontinued. However, they have this model for .308 rifles with standard length M4 receiver extensions that should work: JP Rifles

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- Fourth Horseman -

Thank you, Fourth Horseman, for the info and the pointer to a spring from JP.

Can you suggest a matching buffer to go with it, since I don't really know (or trust) whatever is in the M&P now?

I'd like to get a 'known-good' configuration rather than trying things out one-by-one until I luck onto a winning combination.

Thanks again.

With the JP Enterprises solution you do not need a separate buffer. You replace the existing buffer and spring with the all-in-one unit from JP. It works really well and it's nice and quiet. A little pricey is the only down side.

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- Fourth Horseman -