Looking to get a Magpul replacement stock and am trying to find the answer to my question. I searched the forums and found some posts but no clear answers. One guy says all of the M&P rifles are milspec while another says only the 22s are.
I have a pretty sweet 15T (older model with Troy parts) with an aimpoint Compm4s on it. All I need is a more comfy stock. Any info is appreciated!

In the "Chart" the receiver extension diameter is listed as 1.14
which makes it "milspec" if I'm not mistaken. Stag's is also listed as such and I think they made the earlier M&Ps for S&W.

You might want to measure to make sure. (Commercial is 1.17 )

Thanks for the info. I'm gonna buy a mil spec and hope for the best!

Here's a pic of my baby below. ImageUploadedByTapatalk1303081973.529158.jpg

Its going to be mil-spec, I called S&W a while back and asked customer service the same exact question, the rep stated that the M&P15 line has a mil-spec buffer tube, I have a 15T with a Magpul CTR mil-spec diameter, it fits great.

My M&P15OR is mil-spec....or at least the replacement stock I picked up for it (which fits nicely) is mil-spec.

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Stu

Krap!, I ordered a CTR for commercial spec, it fits with just a little wobble, I don't think I'll spend $10 to send it back for exchange for a 2/1000's difference.

OCD got the best of me, I had another part to return anyways so I sent the stock back to exchange for the Mil Spec one, that was the whole point in getting the CTR, was to get it as tight/stable as possible.

Just to let everybody know, I got the mil spec ACS and it fits like my girlfirends thong. very nice!!!

Why would you want to wear her thong? Geez.....

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Stu

Now, I just came up from the basement after meauring my MP 15 ORC, and it definitely measure 1.170". So I guess S&W has used both mil-spec and commercial. Mine has the fake colapsable stock which I would like to replace with the ACE Skeleton stock on sale at MidwayUSA ACE Skeleton Buttstock 9.9" Overall Length AR-15 Aluminum Black - MidwayUSA . It "uses the standard A1/A2 receiver extension tube, buffer and spring" but makes no mension of whether it fits mil-spec or commercial. Am I missing something?

I think the ACE stocks are like the A2 stock they just screw in to the receiver, the buffer and spring are in the stock.

Interesting. Just took calipers to mine and it is definitely milspec. LOL, the stock rattles enough to be commercial though, mounted on a mil spec tube. Not sure what a milspec stock tunnel should measure so might just be the nature of the beast. Mine is an OR model also, btw. Produced in early Nov, 2010.

I see yours is the C (compliant) version so that may account for the commercial spec. However, I think the stock is the same, just pinned.

I wound up with an ORC model (long story).

It definitely had a commercial spec, non-folding on it. I ordered a complete commercial folder, and it worked fine.


It's confusing, but a commercial, OR mil-spec stock (the complete thing, with buffer tube) will screw right into any lower. While the OD's are different, the screw threads are the same, on both.

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NRA Instructor

That's because the threads on the mil spec receiver extentions are rolled and the commercial are cut threads. Thats why commercial receiver extentions are bigger, they need that extra material so the threads will be big enough.

good to know makes ordering mine easier