M&P-15 and other ARs: What's the difference?

[Rastoff]

Is there anything specifically unique about the M&P-15? I know it comes in several variants, but is there something that sets it apart from other ARs?

 

[fyimo]

There are a lot of Companies making AR-15's and everyone brings out several models at various price points with different features and it's up to the buyer to do his research and buy the one he wants. Then fit it to their needs and one that is at their price point and they should pull the trigger. The AR-15 platform is now mature with most of the problems are worked out so you should look for the features you want and a company with a great reputation and buy it.

 

[cyphertext]

The biggest difference between say a Colt and the S&W is that with the Colt, you get a "mil-spec" or "built to TDP" rifle. In other words, it is a basic carbine rifle that is very close to being the same as the M4 as issued by Uncle Sam, with the main difference being the happy switch and barrel length.

For the same money with S&W, you get more features.... You can sometimes find the M&P 15 MOE for the same price as a Colt LE6920. The S&W uses a semi auto bolt carrier, different twist rates, possibly different barrel treatments like Melonite depending on models.

So, which do you like? Features or "mil-spec"?

 

[Arik]

Oh get ready for 20 pages of TDP is good/ TDP sucks all ARs are the same.

For me, I like TDP. It tells me what and how my rifle is made. There is no guessing and no "a source told me..." comments. TDP is used in battles all over the world and had proven itself. I will only buy that or better. So basically the cheapest AR I'll get would be a Colt. Other ARs that go above TDP are Noveske, DD, Kights..

I know guys who cry when their no name, outsourced, Chinese pot metal parts AR break from using steel cased ammo and they blame the ammo. Now, ifs very possible that the ammo was the culprit but when you don't know what your parts are made off how do you know how good your rifle is.

My LGS is selling new M&P sports for just under $600 OTD. I think they went through a little over 1100 rifles in less than a month. Good price but for a few bucks more I'll take a Colt 5920. To me extra features are irrelevant, fancy rifling is irrelevant. I want a quality rifle with a history of proven performance. To me this is like the difference between a Les Bear, Wilson, Brown, and a Rock Island or Remington R1. Both are fine but there are reasons why some are cheaper than others

Sent from my SCH-I545 using Tapatalk

 

[thecatch8]

M&P is just a solid blue collar black gun. Nothing fancy, nothing great, it just shoots true and goes bang. If I had to do it all over again, I would still choose the 15T as my first AR. I have learned a great deal working and upgrading the rifle, and that has brought me considerable enjoyment. It's all about the journey. Now that I have finished making upgrades, I am in the process of building up a 300 blackout using a Spikes Tactical lower....but you always remember your first!

 

[JaPes]

The biggest difference between say a Colt and the S&W is that with the Colt, you get a "mil-spec" or "built to TDP" rifle. In other words, it is a basic carbine rifle that is very close to being the same as the M4 as issued by Uncle Sam, with the main difference being the happy switch and barrel length.

There are a lot of Companies making AR-15's and everyone brings out several models at various price points with different features and it's up to the buyer to do his research and buy the one he wants. Then fit it to their needs and one that is at their price point and they should pull the trigger. The AR-15 platform is now mature with most of the problems are worked out so you should look for the features you want and a company with a great reputation and buy it.

+1

IMO, the stand-out feature of the S&W M&P-15 line is that it is a civilian AR-15 backed by an established, long term, well known brand that has the resources to back their claims of use and back their warranty.

The second thing I like is the 1:8 5R progressive gain twist, Melonite Treated, Thompson Center barrel installed in some of the line.

Oh get ready for 20 pages of TDP is good/ TDP sucks all ARs are the same.

I can't over generalize that all AR's are the same. I find myself in the middle-ground of the Mil-Spec TDP (technical data package) is the end-all-be-all v.s. TDP is nonsensical in a civilian application debate. Just my opinion:

• An AR-15 stripped lower is built to a standardized size, pins are drilled in standardized locations, the fire control group pocket is milled to standardized dimension, etc.
  
• An AR-15 stripped upper where the bolt carrier group reciprocates and where it mates to the barrel are produced to standardized dimensions.
  
• An AR-15 Bolt Carrier Group is built upon standardized dimensional specifications.
  
• An AR-15 barrel's chamber is reamed to standardized dimensional specifications.

Just my opinion, AR-15 manufacturers' marketing departments do their best to make their rifles stand out. They'll tout small construction differences between this and that to persuade a customer to buy into their marketing hype.

The mil-spec TDP is a good starting point for a civilian AR-15. They're there for a military M16/M4 which is out of reach for most civilian firearms enthusiasts. The common civilian firearms enthusiast settles for an AR-15 configured to mimic a military M4, referred to in slang as an M4-gery. Because the AR-15 is built upon standardized dimensions, there are inexpensive parts on the market that visually look right but are not made from sturdy materials. It takes some experience to be able to discern what is a good part and what is a bad part. This is where comparing a part to the Milspec TDP is handy.

For me, the mil-spec TDP isn't the end-all-be-all of civilian AR-15 construction. It's a starting point. I can use parts on the civilian market that employ new coatings, materials, and assembly details that aren't in the mil-spc TDP. I can get myself a different buffer weight, buffer spring, exotic coatings on the bolt carrier group, exotic coatings on the exterior surfaces of the rifle, 2-stage trigger systems, an upper receiver that has a different exterior profile, etc. I can make these choices, but have to be aware of the minimum requirements. The TDP is a component of that background knowledge. Asking the question "What makes part X different from part Y?" and actively searching for the information is a component of background knowledge.

I know guys who cry when their no name, outsourced, Chinese pot metal parts AR break from using steel cased ammo and they blame the ammo.

To me this is not truly supporting the argument that the Mil-Spec TDP is the bottom line standard of civilian AR-15 construction. It just means that you know guys who do not possess the ability or initiative to employ critical thinking and evaluative skills when making a purchase. There will always be people who do not put in the effort to do a minimum of research to gain some background knowledge before a purchase. It happens with appliances, televisions, computers, cars, etc..

The quality of Chinese manufactured parts and steel case ammo (I'm assuming you mean Russian manufacture steel case bi-metal jacket projectile because Hornady makes steel case ammo now) is a whole different subject on it's own.

My LGS is selling new M&P sports for just under $600 OTD. I think they went through a little over 1100 rifles in less than a month. Good price but for a few bucks more I'll take a Colt 5920.

To me extra features are irrelevant, fancy rifling is irrelevant. I want a quality rifle with a history of proven performance.

If a manufacturer claim to adhere to the Mil-Spec TDP is your primary criteria for selecting a rifle (or parts), it's fine. Colt isn't the sole source for mil-spec TDP rifles. Their marketing department rightfully proclaims that they hold a military contract to produce M4's according to TDP. Don't forget that H&K and FN have military contracts and access to the Mil-Spec TDP too.

It's all just my opinion. All AR-15 enthusiasts will question their 1st AR-15 purchase wondering if they made the right choice. They'll have to sift through the overabundance of unsupported internet opinion (such as mine) to get to credible information. Then they'll have to figure it all out for themselves.

 

[Rastoff]

Thank you JaPes. I had never seen the acronym TDP before so, thanks for explaining it to me. That was a marvelous description.

I'm not an AR geek. I do have a couple, but don't know a whole lot about them. I had no intention to make this a thread about is brand X better than an M&P. I was just curious to find out if there was some feature on an M&P not found elsewhere.

Thanks to the previous post, I know more about the AR than ever before.

 

[JaPes]

Thank you JaPes. I had never seen the acronym TDP before so, thanks for explaining it to me. That was a marvelous description.

Thanks, but that really was an oversimplification. You'll see heated debates over the merits of Mil-Spec TDP. You'll get a few more acronyms ...

HPT = High Pressure Test

MPI = Magnetic Particle Inspected

LFT = Live Fire Tested

Case Hardened / Shot Peened

USGI = U.S. Government Issue

...and that's just some of the Bolt / Bolt Carrier Group. There's 4140 v.s. 4150 steel for the barrel... blah blah blah.... It's like a never ending rabbit hole.


Also I was wrong. The US doesn't own the Mil-Spec TDP.

"Contrary to popular misconception, the US Department of Defense does not own the technical data package (TDP) for either the M4 carbine or its parent, the M16 rifle. In June/67, in its role as the DOD's designated procurement agency, the US Army purchased a license from Colt for the TDP and the rights to produce the M16 family of weapons and its component parts."

Source: Colt M4 Data Rights & The Individual Carbine Competition

^ Nice general background info there. Just don't fall too far into the rabbit hole. It's hard to claw your way back out.

 

[Rastoff]

It's like a never ending rabbit hole.

It's not "like" a never ending rabbit hole, it's the mother of all rabbit holes. Lewis Carroll never dreamed up anything this deep.

I was just hoping to learn something new about the M&P rifles. I never dreamed that I would crack open the bottomless pit. I hope it doesn't go there.

 

[78Staff]

Also noticing in the 6920 post above, really not applicable to compare or generalize a 6920 (a fine rifle, btw) with an S&W Sport. If I wanted to do a comparison of an M&P 15 to the 6920, it would be the Standard model 811000. Or the SoComm to the 15X, for example.

Dollars to donuts, I think one of the best deals going right now on an AR is the VTAC II. What you get for the price ($1350) is pretty amazing. If I bought another AT today it would be the VTAC II for sure.

 

[cyphertext]

Also noticing in the 6920 post above, really not applicable to compare or generalize a 6920 (a fine rifle, btw) with an S&W Sport. If I wanted to do a comparison of an M&P 15 to the 6920, it would be the Standard model 811000. Or the SoComm to the 15X, for example.

Dollars to donuts, I think one of the best deals going right now on an AR is the VTAC II. What you get for the price ($1350) is pretty amazing. If I bought another AT today it would be the VTAC II for sure.

I didn't see anyone reference the Sport or any other particular model above (ETA - sorry see it now...). It really doesn't matter which rifle you pick from the M&P line to compare to the Colt, as all of them use a semi auto bolt carrier vs. the full auto carrier that Colt uses. S&W uses a carbine buffer vs. the heavy buffer found in Colt. Outside of the MOE and VTAC II, all the barrels are 4140 vs. 4150. Most of the M&P line use 1:9 twist vs. 1:7 twist on the Colt. Of course the Sport moves even further from TDP by eliminating the forward assist and ejection port cover.

Do these things make a difference in a civilian, semi auto rifle? We could argue that for days and I doubt anyone would change their opinion.

If we do look at a Sport model only, the thing that set it apart from the rest of the market was the low cost for a complete built rifle from a reputable manufacturer with lifetime warranty.

As far as the VTAC II... I'm with you. If I was in the market, that would be high on the list!

 

[Arik]

Overall this is all fine and I dont have much of an argument towards it. All ARs are the same. They have the same dimentions from one to another. And generally do the same thing. All very true. However!!!

I can't over generalize that all AR's are the same. I find myself in the middle-ground of the Mil-Spec TDP (technical data package) is the end-all-be-all v.s. TDP is nonsensical in a civilian application debate. Just my opinion:

• An AR-15 stripped lower is built to a standardized size, pins are drilled in standardized locations, the fire control group pocket is milled to standardized dimension, etc.
  
• An AR-15 stripped upper where the bolt carrier group reciprocates and where it mates to the barrel are produced to standardized dimensions.
  
• An AR-15 Bolt Carrier Group is built upon standardized dimensional specifications.
  
• An AR-15 barrel's chamber is reamed to standardized dimensional specifications.

Just my opinion, AR-15 manufacturers' marketing departments do their best to make their rifles stand out. They'll tout small construction differences between this and that to persuade a customer to buy into their marketing hype.

The mil-spec TDP is a good starting point for a civilian AR-15. They're there for a military M16/M4 which is out of reach for most civilian firearms enthusiasts. The common civilian firearms enthusiast settles for an AR-15 configured to mimic a military M4, referred to in slang as an M4-gery. Because the AR-15 is built upon standardized dimensions, there are inexpensive parts on the market that visually look right but are not made from sturdy materials. It takes some experience to be able to discern what is a good part and what is a bad part. This is where comparing a part to the Milspec TDP is handy.

THIS ^. That is my problem. With so many manufacturers out there fighting for the same market share leads to a lot of cost cutting. While the parts may all be of the same dimantions their raw materials are often lacking in quality. Just google any AR part and you'll find 500 companies making it. Quite a few of those parts are airsoft. Some have almost no QC.

For me, the mil-spec TDP isn't the end-all-be-all of civilian AR-15 construction. It's a starting point. I can use parts on the civilian market that employ new coatings, materials, and assembly details that aren't in the mil-spc TDP. I can get myself a different buffer weight, buffer spring, exotic coatings on the bolt carrier group, exotic coatings on the exterior surfaces of the rifle, 2-stage trigger systems, an upper receiver that has a different exterior profile, etc. I can make these choices, but have to be aware of the minimum requirements. The TDP is a component of that background knowledge. Asking the question "What makes part X different from part Y?" and actively searching for the information is a component of background knowledge.




To me this is not truly supporting the argument that the Mil-Spec TDP is the bottom line standard of civilian AR-15 construction. It just means that you know guys who do not possess the ability or initiative to employ critical thinking and evaluative skills when making a purchase. There will always be people who do not put in the effort to do a minimum of research to gain some background knowledge before a purchase. It happens with appliances, televisions, computers, cars, etc..

True, but you cant google "what materials is my Double Star mad off" Unless someone really took the thing apart and analized it to death.

The quality of Chinese manufactured parts and steel case ammo (I'm assuming you mean Russian manufacture steel case bi-metal jacket projectile because Hornady makes steel case ammo now) is a whole different subject on it's own.





If a manufacturer claim to adhere to the Mil-Spec TDP is your primary criteria for selecting a rifle (or parts), it's fine. Colt isn't the sole source for mil-spec TDP rifles. Their marketing department rightfully proclaims that they hold a military contract to produce M4's according to TDP. Don't forget that H&K and FN have military contracts and access to the Mil-Spec TDP too.

Absolutely. Which is why I said Colt is the CHEAPEST TDP rifle. There are a bunch of companies that make rifles and parts that go above and beyond TDP but that is also reflected in their price.

It's all just my opinion. All AR-15 enthusiasts will question their 1st AR-15 purchase wondering if they made the right choice. They'll have to sift through the overabundance of unsupported internet opinion (such as mine) to get to credible information. Then they'll have to figure it all out for themselves.

I consider most ARs below TDP to be kinda like shopping at Harbor Freight. Most tools are fine for the occasional do-it-yourselfer. Just to have tools incase some plumbing needs to be done, some bolts tightened...etc...etc....but those same tools are nowhere near the quality steel of say SnapOn or other more expansive tools. And dont be surprised when the Harbor Freight tool breaks or fails before the more expansive one does. There is a difference when a tool is cut and shaped from stock and when one is just poured into a mold.

Why I like TDP is because it tells me this. I can choose to go higher but I know where I stand

 

[JaPes]

Arik,

I agree with you. The one aspect of written communication is the absence of non-verbal communication cues such as tone of voice and body language. If this convo were happening I the real world, we'd all be having a friendly conversation over a beer. For the uninitiated, sticking to a rifle that meets the trade secret TDP is a good start. Sticking to a complete rifle from one of the big name brand manufacturers is a good start.

What gets under my skin are people who base decisions solely on price point. I've seen the extremes. I've seen people buy the least expensive rifles made from parts supplied and manufactured by unknown companies, and are bewildered when it fails. I've seen people buy the top of higher price range AR-15's believing that the $$$ spent on equipment alone will turn them into the next Carlos Hathcock. It gets annoying.

I'm right in hot he middle. Buy a rifle that suits your budget, current skill level, and from a well established reputable manufacturer.

 

[cyphertext]

Arik,

For the uninitiated, sticking to a rifle that meets the trade secret TDP is a good start.

I don't need no secret sauce!

To me, TDP calls for a certain specification to meet a particular application. However, most of the time, my usage is not the same type of use that TDP is made to cover.

I don't want to go down the rabbit hole and start the 20 page "discussion", but barrel steel is a good example. Mil-Spec 11595E barrel steel is designed to perform under stresses and environmental conditions that most civilians will not find themselves in. For most shooting, you would not see much difference between the mil-spec barrel and a 4140 Ordnance barrel from a reputable manufacturer with good QC.

And if you are a NRA high power shooter, or some other bullseye competition, you may choose a stainless or unlined barrel for accuracy, with a different twist rate. It all comes down to specifications meeting your intended use and application.

But I bought the Sport because it was cheap!

 

[Rastoff]

I have to admit, I never thought of the material itself when talking about the upper or lower. I don't think I'll ever be in a situation where my gun is being run over by a truck so, I'm not sure it matters. I know the lower doesn't take a lot of stress therefore, I see no reason to spend a mint on one. Someone correct me if I'm wrong.

About barrels, I have no clue what those numbers mean. Could someone clarify what they are and why one might be better than another?

 

[Maddmax]

I don't need no secret sauce!

It all comes down to specifications meeting your intended use and application.

No secret sauce here either. I buy for survivability. If I have to grab what ever I can get my hands on and beat feet when SHTF, I want 99.9% reliability of a known product with a good track record.

All Mil-Spec means to me is interchangable parts if needed.


As for what's specifically unique about the M&P-15... Low price and it will give the "big boys" a good run for the money. Cheap in cost, NOT in quality.

 

[cyphertext]

I have to admit, I never thought of the material itself when talking about the upper or lower. I don't think I'll ever be in a situation where my gun is being run over by a truck so, I'm not sure it matters. I know the lower doesn't take a lot of stress therefore, I see no reason to spend a mint on one. Someone correct me if I'm wrong.

About barrels, I have no clue what those numbers mean. Could someone clarify what they are and why one might be better than another?

For the most part, a forged lower is a forged lower. Depending upon who does the final machining could affect the quality, but most manufacturers are using the same grade aluminum.

As far as barrels, there are 3 acceptable barrel alloys under Mil-Spec 11595E. Two of them are different "grades", for lack of a better term, of 4150 steel, and the third is an alloy called CMV, or Chromoly Vanadium Steel. The difference between these and 4140 Ordnance is additional carbon or vanadium to add strength to the barrel.

As far as the number, the last two digits on 4140 and 4150 designate the carbon content in hundredths of a percent. So, rule of thumb, 4150 has .10% more carbon than 4140 steel.

This extra carbon or vanadium adds strength and heat resistance to the barrel. It allows the barrel to withstand heat build up from auto or burst fire. It also lessens the chance of a stress fracture caused by a hot barrel meeting with snow, ice, or cold sea water.

It is a more durable metal, but also more expensive than 4140 and harder to cut and work with. Just because a barrel is made of 4150 steel though does not automatically make it better than 4140. You have to have good QC during the heat treatment of the barrel, as well as cutting the rifling, etc. I would go with a 4140 barrel from a known good maker before I would go with a 4150 barrel from an unknown manufacturer that I found on the net.

I'm sure an engineer or metallurgist could explain it better, but that is my understanding.

 

[JaPes]

...and down the rabbit hole we go...

 

[Rastoff]

Thanks cyphertext.

...and down the rabbit hole we go...

Well, I'll take the blame. I did ask the question.

 

[JaPes]

Sometimes the rabbit hole is the only way to learn...

The 4140 v.s. 4150 ordinance steel is another fun tangent. 4150 is harder to withstand burst fire / full auto. The trade off is a more brittle steel. 4140 is less brittle a bit more "flex", which is acceptable because civilian AR-15's aren't intended for full auto or burst fire.

Then you get into the chrome lined v.s. non lined discussion. Chrome lining is an additional material added to the bore. The bore is reamed to account for the additional material, but any additional material in a bore degrades potential accuracy. It's also an expensive process. Non chrome lined bores are more accurate.

Then throw in hot salt bath nitrididing processes with trade names such as Melonite and Tennifer into the mix. Then you're getting an unlined barrel with hardness and wear protection properties of chrome lining.

....help... I've started to fall back into the rabbit hole and I need a to climb out! LMAO