S&W M&P10 Upper Compatability? W/Pictures added 8/4/13

[prairie]

Is there any upper/lower compatability with other brands of AR10 types?

 

[Blueapplepooh]

From what I have heard, there is not.

I found a video on Youtube and this gentleman explains what he found out during his build around 12 minutes into the video.

Smith & Wesson M&P10 Modifications - YouTube

 

[prairie]

Have been doing a little more research, and it looks like the guy on the video has it pretty well nailed down.
Seems the S&W upper receiver/barrel assembly is pretty much all proprietary, with very little interchangeability of parts.
Being so new, It may be a little while before M&P 10 aftermarket parts start showing up. Hopefully the barrel upgrade issues will be addressed soon.

 

[Drag]

There doesn't appear to be a mil-spec standard for the AR10 platform. Each manufacturer is kinda doing their own thing. Other manufacturers like Rock River Arms have disclaimers on their sites regarding compatibility:

Rock River Arms: NOTICE - RRA LAR-8 Parts Interchangeability

With that said, I do hope that S&W does release other barrel options down the road. I'd personally like to buy a heavy varmint or match barrel upgrade.

 

[DocMufasa]

I've found online that the m&p10 is dpms based, the rail I gt was for a dpms low profile upper. Ill try my upper on my buddy's dpms lower later this week

 

[Arizona_Mike]

I've found online that the m&p10 is dpms based, the rail I gt was for a dpms low profile upper. Ill try my upper on my buddy's dpms lower later this week

How did the test go? A lot of people are anxious to know.

Mike

 

[Arizona_Mike]

Bueller? Bueller? Bueller?

http://www.youtube.com/watch?v=KS6f1MKpLGM

 

[prairie]

Got a hold of my brothers DPMS 308 and tried mixing and matching uppers.
The S&W upper will pin up to the DPMS lower, manually functions and dry fires. The bolt catch on the left side hits the receiver and would require grinding a shallow depression in the upper to work properly. There is also a noticeable gap between the upper and lower receivers.
After the receiver is relieved for proper bolt catch function, I think there is a good chance that it would fire and function with no problem.
The DPMS upper was a tight fit on the S&W lower, and the bolt seemed to protrude from the receiver farther than the S&W and would require pushing the buffer assembly in over 1/8" to get it in position to pin up. Also the right side of the upper receiver would need a relief cut , similar to the existing one on the left side, for the bolt catch. If that were done , it would likely pin up, and manually function and dry fire.

I'll post pictures tomorrow when my 15 year old tech support son is available.

 

[prairie]

S&W Upper on DPMS Lower


S&W M&P-10 Upper on DPMS .308 Lower

You can see the bolt catch has pressure on it

closer image of the bolt catch

gap in between DPMS lower and S&W upper

DPMS bolt catches on the S&W buffer

 

[prairie]

S&W on DPMS

Bolt held open

 

[Arizona_Mike]

It looks like it is hanging up on the edge of the buffer and might just be the radius on the bottom rear of the bolt carrier. Are you able to push the buffer back and close the DPMS upper on the S&W lower?

Mike

 

[prairie]

I think the buffer could be pushed back allowing it to fit, but the bolt latch on the right side of S&W lower would hit on the DPMS upper. I think it would fit, manually cycle and dry fire if the right side bolt latch were removed.

 

[Arizona_Mike]

Thanks for taking the time to document the issues. Any truth to the rumor about the front (or rear) pin lug being a different width?

Mike

 

[prairie]

Thanks for taking the time to document the issues. Any truth to the rumor about he front (or rear) pin lug being a different width?

Mike

I'll have my son disassemble both guns and take pictures of various parts side by side, and get the pictures posted to this thread. It might be next week, as our county fair just started and he has 4-H, Boy Scout, and "other" activities to participate in at the fair.

 

[Arizona_Mike]

Sounds great. Good luck to your son at the fair.

Mike