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

Well, in the end, Alice did have a good time even if it was sometimes terrifying.

I didn't realize that some barrels had the Melonite treatment. I've had that on a few pistols and like it very much. I will have to do some more research. Now I'd like to get my hands on a barrel with this treatment.
 
Rastoff said:
I didn't realize that some barrels had the Melonite treatment. I've had that on a few pistols and like it very much. I will have to do some more research. Now I'd like to get my hands on a barrel with this treatment.
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Melonite and Tennifer are tradmarked names. S&W used to explicitly list their barrels as Melonite treated. Then the trademark holder of Melonite wasn't happy about it. S&W now uses terms like "maximum corrosion resistant treatment" and such.

Here's more rabbit hole for ya...

Ferritic nitrocarburizing:

Ferritic nitrocarburizing - Wikipedia, the free encyclopedia

S&W acquired Thompson Center which led to some of the S&W M&P 15 lineup to have the 1:8 5R progressive gain twist Melonite barrel.

5R_zps57296a44.png


Side note to new members: We discuss all these trivial details just for the heck of it. Some people take it too seriously. For example, on paper the 1:8 5R rifling seems like god's gift to rifling. In range use and out to 100 yards, I see no practical difference between my 1:8 5R barrel and my 1:9 barrel. I don't even see any noticable ease of cleaning. I just like having the info in my noggin. The more background knowledge I have, the better off I am.
 
cyphertext said:
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.
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I read a few articals awhile back on forged lowers. Seems a few manufactures make them (to what ever standard for different companies) and the only difference on "most", is just the "magic name" stamped on the side and the final machining. It was quite an interesting read.
 
Rastoff said:
Since we've headed down the rabbit hole....

Anyone ever use one of those polymer lowers? If so, comments?
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That's a different rabbit hole altogether... I've never used one, but I don't think I would on anything other than a .22lr. I think there would be too much stress at the front pivot pin for heavy use or long life.

There is a boy in my son's boy scout troop that ordered one of the 80% polymer lowers and finished it out with a dremel. I hope to get to shoot it sometime and maybe it will change my mind.
 
Rastoff said:
Since we've headed down the rabbit hole....

Anyone ever use one of those polymer lowers? If so, comments?
Click to expand...

I shot a center-fire AR-15 with a polymer lower a couple years ago. It was a DPMS oracle. I could swear that it felt like it vibrated wrong under live fire. It was a feeling.

https://www.youtube.com/watch?v=NHbYjHBJmB0

The polymer AR-15 receiver flexes more than a standard forged receiver. The buffertube flexes, barrel, it even wiggles laterally. There was a slow motion video comparing a polymer and a forged lower under hi-speed and the difference was stunning. I wish I bookmarked or copied the video. For the life of me I can't find it.

Would I use a polymer lower? Maybe... maybe not. In the case of the AR-15 I'm a traditionalist: give me forged aluminum. I have been tempted to monkey with an 80% polymer lower and build my own, personal use, government please may I form free AR-15.
 
Modern Sporting Rifle.

Firearms enthusiasts are encouraged to use the term to describe civilian semi automatic firearms modeled after their full military spec counterparts. It's a less inflammatory name than the term "assault rifle" bandied about by the mainstream media.
 
Thank's John. :)

Rastoff. It stands for Modern Sporting Rifle.

The News Media and Libtards are always getting things wrong. "We" are just trying to keep things in the right perspective. :)

They (media) can't/ /don't even know the difference between a back-hoe and a bulldozer or a wheel loader and an excavator.
 
Rastoff said:
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.
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You have to remember. That (lower) is where the buffer and spring are slamming back and forth being hammered by the BCG (Bolt Carrier Group) every time you squeeze a round off. That shock does run through the whole lower too.

You also want all those parts, safety, trigger group, mag release, pins, springs, take down pins to be held and stay in place. Mag well to stay lined with the upper so the mag seats for feeding rounds...

...and chances are, if any MSR gets run over by a truck. It's party will be over.
 
Arik said:
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
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So then.... YOU have a copy of the TDP???:confused:

That would be rather amazing, because during the last series of ICR tests (Individual combat rifle) even competitive companies like Sig Sauer, LWRC could not get THEIR hands on a full TDP. They had to reverse-engineer the existing rifles which were samples, and go from there.

And in the end, Colt is now???3rd place. Remington won the .mil contract, Colt cried over the loss of said contract, and FN took the contract on the rebid. Linky: http://kitup.military.com/2013/02/army-awards-m4m4a1-contract-fn.html

Down the wormhole. The M249 SAW uses a 4140 barrel. :p So unless one would expect to subject their personal rifles to that kind of punishment, I'd say it were a stretch to throw about the idea that the difference between the 2 materials is so great as to warrant an immediate dismissal of one over the other.

There are no rifles completely made in house by one manufacturer solely. Everyone is subbing out for parts. All this has been gone over before. The differences in many of the parts is the level by which the parts are tested.

As to the query on polymer lowers? I am not that interested. They have proven to crack time and time again under relatively low cycling counts. The bolt movement is such on an AR that there is more stress than a Glock will ever create on it's contact points. If one were to get an 80% for dirt cheap ($25ish) then it would be worth milling one out and keeping it for a rainy day or for making a 22lr out of it.

I'm going to stay in camp with Cypher and JaPes, and go with what I have, shoot it some more (16K rounds seems like a lot, until you really think about it, and then you say "That IS a lot!" So, the Sport is pretty well vetted at this point) but if I can figure when it hits the 20K mark I will throw a party.:rolleyes:
 
Rastoff said:
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.
Click to expand...

The front pin area takes a beating and is known to be a stress point which cracks, and the rear pin hole has some tendency to oblong and guys tend to use anti-walk pins over time to keep the pins in. The buffer tube neck has a tendency to crack, and believe it or not, I tinkered on one a month ago which literally was super-glued there.... and still limping along. A spectacular advertisement for super glue..... not so much for a BM Carbon lower.
 
I wouldnt say its a copy. Its just missing the select fire and a shorter barrel, which i can legally get in my state. Yep and if the worst company followed TDP I'd buy that too, cause it would be no different than Colt. Until then I don't see where the savings are. I can buy used Colts for about the same price as M&Ps. My last Colt cost me a whopping $670

Sent from my SCH-I545 using Tapatalk
 
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Arik said:
Yep and if the worst company followed TDP I'd buy that too, cause it would be no different than Colt. Until then I don't see where the savings are. I can buy used Colts for about the same price as M&Ps. My last Colt cost me a whopping $670

Sent from my SCH-I545 using Tapatalk
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Yup. The after affect of panic buying on credit. Some bought just to have one before they got banned. Some bought multiples on credit hoping to pull off a post ban sale profit similar to pre 1986(?) full auto firearms.

The best time to buy is after a panic. Credit bills come due, used rifles glut the market bringing down the prices of both new and used rifles.
 
rojodiablo said:
Down the wormhole. The M249 SAW uses a 4140 barrel. :p
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I don't know for sure, but I had read somewhere that the SAW uses the same steel as the M4, but the chrome lining is twice as thick.

Noveske made some AR barrels this way...
 
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