Smith and Wesson M&P 15 upper receiver

[Acoby]

I recently purchased a M&P 15 and am looking into adding something's to it and am thinking about changing the upper receiver can I put any other smith and Wesson upper receiver on it or are the lowers different?

 

[cyphertext]

You can put a different upper on it, but why? What did you buy, and what do you hope to gain by putting a different upper on it? Most of S&W's uppers have the same barrel, and all have the same bolt and carrier. You don't have to change the complete upper to change things like the handguard.

 

[BillyJack2012]

Curious as to why you would change the upper? More curious as to why you just bought it if you were going to go through the hassle of changing it.

 

[WilsonFlyer]

Maybe he's using a registered lower receiver to change calibers. There are many uppers compatible with the AR milspec lower.

Am I missing something between the lines here that I obviously didn't see? You guys seem hyper-critical of the question.

Actually, I've often wondered if the M&P 10 lower is any different (more solidly built) because one of the uppers I've often debated putting on my M&P 15 is a .308.

The obvious answer is that any milspec upper will work with the M&P 15 lower because it is standard.

Changing uppers is one of the obvious advantages of the AR platform because the lower is the registered component.

 

[WilsonFlyer]

Curious as to why you would change the upper? More curious as to why you just bought it if you were going to go through the hassle of changing it.

What's the hassle? Pulling two pins? That's kinda the whole point.

 

[vipermd]

The M&P 15 does not fit on M&P 10. As stated by WF you can put any caliber , mil spec upper on it. Be Safe,

 

[Acoby]

I am just wondering for the future use of the rifle, without the forward assist and dust cover I was wondering if the rifle would benefit from a upper containing those things or if they are just bonuses that don't change much.

 

[Mustang5L5]

Smith and Wesson M&P 15 upper receiver

I'm going to assume he means changing out the dust cover and FA-less reciever for one with a dust cover and FA. Yes, the upper receiver can be changed to any quality AR15 style upper you want.

I changed mine out a while ago to a Spikes Tactical upper when prices fell on parts after the rush. I used the original upper for a lightweight .22 build since I did not need a FA or dust cover for it.

Since I bought my m&p15, its parts have been scattered around to a few rifles I've build now. Only original parts on my Sport are the 1/8 barrel, and lower reciever and parts group.

Nothin really gained by swapping the upper reciever other than just gaining some build experience.

Ignore the crappy optic, but this used to be a sport.

Sent from my big *** iPhone 6 using Tapatalk

 

[cyphertext]

Am I missing something between the lines here that I obviously didn't see? You guys seem hyper-critical of the question.

We seemed critical of the question because of what was asked... he didn't ask about changing calibers... He asked if he could change uppers because he was "looking to add somethings to it". If those things were different handguards, rails, sights, flashguard, etc., then it makes no sense to change the upper.

 

[cyphertext]

I am just wondering for the future use of the rifle, without the forward assist and dust cover I was wondering if the rifle would benefit from a upper containing those things or if they are just bonuses that don't change much.

The fact that you are asking about them to me says that you don't need them... not trying to be rude, just you aren't trained in the old school military manner, and I am not saying that is a bad thing.

There are many "discussions" about the forward assist and the ejection port cover. Newer training courses do not use the forward assist. My Sport has not experienced a jam that would have been negated by the use of an ejection port cover. If you want these things, you can add them by buying a stripped upper and swapping parts out of your rifle to complete the stripped upper.

 

[ChattanoogaPhil]

You can put any milspec upper on your lower. You can also put some .22LR uppers on it like CMMG.

That's the great thing about these rifles, with enough money there is no limit to what you can put on that lower.

 

[sgtsandman]

Actually, I've often wondered if the M&P 10 lower is any different (more solidly built) because one of the uppers I've often debated putting on my M&P 15 is a .308.

The upper and lower on SR25/LR308 and AR10 platforms are larger than the equivalent uppers and lowers on an AR15, so those parts can't be swapped between the two. Hand guards, gas blocks, stocks and most of the other components can be swapped on the other hand.

To the OP, the M&P15 follows the same specifications that other AR15s do, so the general answer is yes you can swap uppers for different ones. Depending on what you want to do, you may need to get a complete upper with a bolt carrier group to do it. Say, 7.62X39 as an example since the base of the brass is different from .223/5.56 and will not work with the standard BCG but you can still use the same magazines.

 

[BillyJack2012]

Talk about being critical.... Man, was just curious and asked why he wanted to change the upper RECEIVER as stated, not COMPLETE upper. That requires more than just pulling a couple pins. As I thought, it was simply due to the fact that he wanted the FA and Dust cover.

For the most part, change of caliber requires a new upper receiver, barrel, bolt etc. and none of that was even asked.

The Sport upper is rock solid and to change it out to gain a dust cover that will likely never be closed (sure, tell me all about how you close your dust cover all the time before and after range trips) and a FA that will likely never be used doesn't make a whole lot of sense. This forum is here for guidance and by simply answering questions without understanding the intent behind them doesn't help much. People don't know what they don't know. Guess that's the consultant (what pays the bills) in me coming out.