Smith & Wesson M&P15X Info Thread.

Last Summer I purchased my very first AR, a Smith & Wesson M&P15X police trade-in. I was previously unaware of the existence of this particular model, and although I've spent the better part of a year attempting to research it, information has been rather thin and required a surprising amount of effort to find even the most basic of details on, despite the fact that it's still listed in S&W's catalog.

http://web.archive.org/web/201911011...irearms/mp-15x
https://www.smith-wesson.com/product...forcement-only

Here's what I've gathered so far...

SPECIFICATIONS

Model: M&P15X
Product Code: 811008 (Gen 1)
Caliber: 5.56x45 NATO
Barrel Length: 16"
Barrel Twist: 1 in 9" (Gen 1) / 1 in 8" 5R (Gen 2)
Flash Suppressor: A2 Birdcage (Gen 1) / S&W Custom Flash Suppressor (Gen 2)
Front Sight: A2 Post
Rear Sight: Troy Folding Battle Sight (Gen 1) / Magpul MBUS (Gen 2)
Stock: 6-Position CAR
Weight: 6.5lbs
Barrel Material: 4140 Steel
Barrel Finish: Melonite (Gen 1) / Armornite (Gen 2)
Receiver Material: 7075 T6 Aluminum
Receiver Finish: Hard Coat Anodized Black
Chromed Components: Barrel Bore, Bolt Carrier, Chamber, Gas Key, Firing Pin
Special Features: Troy Carbine Length Quad-Rail Handguard (Gen 1) / Magpul M-LOK Handguard (Gen 2)
MSRP: $1379.99 (Gen 1) / $1239.99 (Gen 2)
Release Date: December 2007 (Gen 1) / April 2017 (Gen 2)

Beyond this I've discovered that the BCG was originally made by LMT, followed by Microbest on later revisions. As listed in the specs there were two separate versions of the M&P15X, but oddly enough only the first generation model is listed in the catalog, so evidently the second generation models were phased out at one point.

Unfortunately, many other details remain unknown. It's unclear if this model was commercially available or strictly Law Enforcement Only. Details regarding what sort of buffers they shipped with are undocumented. (Carbine? H1? H2?) Precise information regarding the composition of small parts is undocumented. (Machined or MIM?) What's the barrel profile? (M4 or SOCOM?)
Alas, my example isn't accurate as a point of reference as it has clearly been modified from the stock configuration in a number of ways by the PD, so it's impossible to tell what's original and what is aftermarket.

I would also be very interested in learning how the M&P15X compares to other models of M&P15 including the Tactical, PC, and Sport models, as what is listed above doesn't seem to justify the hefty difference in MSRP between the M&P15X and other models.

Any additional information would be appreciated.

It may exist to be a separate sku for LE dealers. For example, the M&P Compact .22 is (or was, when I bought one) commercial only, so my dealer couldn’t get them through their normal distributor. Smith LE dealers (or is it distributors?) can potentially sell to other slices of the genpop pie, like EMS, Fire, Military. The specs are weird….they both chromed AND melonited a 4140 bbl? Looks like they merged two product pages and the website dude got confused.

Quote:

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Originally Posted by 1168

It may exist to be a separate sku for LE dealers.

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This is also my understanding with Smith & Wesson LE models, the town/Suburb above us issued out the M&P15 Magpul Mid-Gas version, the only difference is that LEO guns came with all black Magpul MOE furniture. I believe all their pistols (M&P40s) came with factory night sights as well which was a LEO specific model

https://www.vanceoutdoors.com/products2.cfm/ID/112486

Quote:

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Originally Posted by 1168

It may exist to be a separate sku for LE dealers. For example, the M&P Compact .22 is (or was, when I bought one) commercial only, so my dealer couldn’t get them through their normal distributor. Smith LE dealers (or is it distributors?) can potentially sell to other slices of the genpop pie, like EMS, Fire, Military. The specs are weird….they both chromed AND melonited a 4140 bbl? Looks like they merged two product pages and the website dude got confused.

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The barrels are indeed 4140 steel, nitrided, AND chrome-lined! Yeah, it's weird as heck that they'd use 4140 over 4150, nitride the barrels, then chrome line them, but I've confirmed it via multiple sources, all of which were official.

https://www.m4carbine.net/attachment...8&d=1712768447

My only guess is that since the M&P15 isn't offered in a full auto configuration, they don't feel the need to use 4150, yet still go the extra mile when it comes to finishing the barrel.