How does Law Enforcement manage to get by with M&P15s?

[shadowspirit]

No idea. It's Smith's designation. But it CLEARLY illustrates that they tossed the TDP out the window and said "how cheaply can we build this turd?"

The fact that Smith gave it its own designation, AND lowered the price tells me they knew it was substandard. Shit was going wrong on that gun, that I'd never even thought about.

I mean... who thinks their mag catch will break mid shoot?

The mag catch breaking isn't good, obviously. I don't know whether it was an anomaly or not compared to other examples of the same make and model.

One review I read describe the main difference between the m&p sport and the patrol carbine was upgraded furniture.

I did find a S&W listing for the patrol (LEO only) carbine and it's still a 4140 melanite barrel and no other materials specifications listed.

I guess it is possible the difference between the M&P Sport and the M&P Patrol Carbine is just the furniture. Is the Patrol Carbine being priced higher only to give one the impression it is made better. I don't know.

I don't know how much difference there is between the 4140 melanite barrel and the 4150 chrome lined barrel there is. Is the longevity of the prior almost as good as the later if there is no full-auto fire or mag dumps? Is the later significantly or much better than the former only if full-auto and mags dumps are performed?

[lysander]

It is incumbent upon anybody spending other peoples money to spend it wisely.

If a service carbine shoots 400 rounds a year, it will be 15 years, or more, before it shoots out a melonited 4140 barrel (barring mag-dumps and other abuse). Does it make fiscal sense to buy a chrome plated CMV hammer forged barrel that can withstand mag-dumps and regular full-auto use to 7,000 rounds? (And, a nitrided/Melonite treated barrel will be far more resistant to corrosion than a phosphate coating, that will factor in to than 15 year life, and overall life-cycle cost.)

If it does not meet your accuracy requirements, that is an entirely different argument, that will revolve around "What are your accuracy requirements? And are they realistic?"

All choices are going to be a compromise.

I have found that electronics are a different animal altogether. You are usually not provided the required information to make informed decisions, and since most of the critical point in electronics are done by humans, and not intrinsic material properties, cost (which is directly related to workmanship) is more important.

[markm]

The mag catch breaking isn't good, obviously. I don't know whether it was an anomaly or not compared to other examples of the same make and model.

For sure. And had it been only one of the 4 things that had failed on the gun, I'd have likely considered it a one-off. But crap just kept going wrong on this thing. This was 3-4 years ago maybe? Not sure if there's still a Sport offering or if it's any better or worse.

[ACE31]

Could not say as we only use Colts. lol

[ChattanoogaPhil]

Seven years ago...

https://www.m4carbine.net/showthread...port-II-Review

[lysander]

Seven years ago...

https://www.m4carbine.net/showthread...port-II-Review

-barrel specs aren't great (4140, and Lord knows the other specs as they couldn't provide them) - I have discussed this and it is not that critical
-weak staking on the castle nut - If we were going to fight Charlie in the jungles for weeks at a time away from maintenance support, this might be a problem, but patrol duty where you can get things checked out before you roll, this in a non-issue.
-unknown receiver extension specs - see above
-unknown bolt specs (it's MPI and 158C but otherwise unknown) - Discussed.
-finish is unmatched (mis-matched?) - Cosmetic, you still do get what you pay for.
-barrel has machining marks - Even less of a cosmetic issue.

[lysander]

So does that mean Ruger, Core 15, DPMS, ArmaLite, etc etc are also okay?

Not necessarily.

Each manufacturer must be evaluated on their own merits, and limitations.

Again, a $4,000 dollar custom rebuilt pistol is going to be more accurate, more reliable, and faster on the follow-up, but would it be a better choice for your department than a standard Glock 17?

[Echo40]

What is different about the S&W Sport ARs from the other ones being referred to in this thread?

This isn't particularly easy to answer because there are multiple generations as well as intergenerational revisions of the M&P15 Sport, but here are the basic changes...

M&P15 (1st Generation)
Slimline, heat-shielded hand guards
CMT BCG
4140, Chrome-lined, Phosphate-treated 1/9 M4 Profile Barrel
Made by Stag Arms

M&P15 (2nd Generation)
Slimline, heat-shieled hand guards
LMT M16 BCG
Microbest Semiauto BCG (Rev 1)
4140, Chrome-lined, Melonite-treated 1/9 M4 Profile Barrel
Made in-house by Smith & Wesson

M&P Sport (1st Generation)
No Forward Assist
No Dust Cover
CMT Semiauto BCG
Slimline, non-heat-shielded hand guards
6061 Buffer Tube
4140, Melonite-treated 1/9 Barrel

M&P Sport II (2nd Generation)
Microbest Semiauto BCG
Slimline, non-heat-shielded hand guards
6061 Buffer Tube
4140, Melonite-treated 1/8 5R Barrel
4140, Armornite-treated 1/9 Barrel (Rev1)

M&P Sport III (3rd Generation)
Microbest BCG
Free-floating MLOK Rail
Mid-length Gas System
4140, Armornite-treated 1/7 Pencil Barrel

I guess I'd rather have an m&p 15 then no carbine, but I'm a bit surprised at some of the responses here.

It's like materials and the "TDP" quantifiable items don't matter anymore.

If S&W ever made a M&P-15 with TDP type alloys I have not seen one been able to find it online.

All the ones that I can find listed are:

- 4140 barrels
- Non-chrome lined
- No mention of bolt alloy, which nearly always means 9310
- no mention of receiver extension alloy which nearly always means 6061

And those are just the things we can quantify, we'd have to look at the fire control group castings, bcg staking, and similar to know if they've cheaped out in another areas.

A 4140 melonite barrel certainly will shoot, and will likely serve them. Similarly, 9310 bolts.

But thats not the core question, which is why do we recommend 6920s and similar? Or is the m&p " just as good as". Just those items listed alone could justify the $100-200 price difference.

They may certainly be "good enough" for LEO on a budget. Most likely will be carried a lot and shot little.

But it's a far leap to say that they're just as good as a properly tdp'ish carbine.

It depends on the model what parts are made of which. Earlier Receiver Extensions were 6061, as were the Sport Models, but their higher end models were typically 7075.
Likewise, some higher end models were Chrome-lined, Bolts were typically Carpenter 158.

For example, I own an M&P15X, a high-end ($1379 MSRP) model with a Chrome-lined Chamber, Barrel, Bolt Carrier, Gas Key, and Firing Pin. 7075 T6 Receiver Extension and a Carpenter 158 HPT/MPI Bolt. It was extremely difficult to dig up this info because Smith & Wesson isn't consistently forthcoming about who supplies their parts or what materials they're made from on their website nor in civilian catalogs, but the information can be found.

http://web.archive.org/web/201911011...irearms/mp-15x

[kirkland]

For example, I own an M&P15X, a high-end ($1379 MSRP) model with a Chrome-lined Chamber, Barrel, Bolt Carrier, Gas Key, and Firing Pin. 7075 T6 Receiver Extension and a Carpenter 158 HPT/MPI Bolt. It was extremely difficult to dig up this info because Smith & Wesson isn't consistently forthcoming about who supplies their parts or what materials they're made from on their website nor in civilian catalogs, but the information can be found.

http://web.archive.org/web/201911011...irearms/mp-15x

4140 barrel steel, 1/9 twist. So even the high end S&W at $1400 isn't up to the same spec as a $800 6920

[the AR-15 Junkie]

Wonder how many M&P rifles S&W take back in for repair under their Lifetime warranty?