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M&P10 after mods

cb4017

Private
Full Member
Minuteman
Jul 17, 2012
48
15
70
Nevada
My parts arrived so I thought I would share a few details of my M&P 10 modifications. I got in a YHM clamp type low

profile gas block, a 12" Troy TRX-308 handguard and a VLTOR IMod buttstock.

Here is the upper receiver in the vice and ready to dismantle. The receiver blocks are from Armalite and will work on AR15

and AR10 flat-top uppers.
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Barrel nut removed. There was a good bit of grease on the threads.
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Torquing the TRX barrel nut. It only took about 40 foot pounds to line things up.
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The handguard cap was .032 thick so that was how far I was going to gap the gas block.
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Setting the gas block.
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Got busy an forgot to take pics of the finish. Everything went together well. There is very little clearance between the

bottom of the gas block and the inside of the rail so I will be changing the gas block for another.

Here is the finished product.
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I put another 40 rounds through it today. No malfunctions and it will still shoot MOA or better with good ammo when I do

my part. I patterned some 60s vintage TW and LC ball ammo today which shot 2-3 MOA.
 
Nice setup you have going on here.
My MP10 is in enroute to my FFL. Can't wait.
I'm thinking a Carbon Fiber Handguard to keep it light weight for a carry around hog killing stick.
I was fixing to order the YHM Gas Block you have in the pic.
What Gas block are you going to change to, to get more clearance?
What scope are you using there?
 
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I am working on getting the parts together for a free float fore end on my M&P10. I noted your remarks on the gas block being tight under the Troy, as I had the same issue putting a Troy on my M&P15 Sport.
Those Troy Alphas are pretty small diameter.
Nice looking finished product you have too.
 
Thanks Gents. I'm pleased with how it turned out. Even at retail I think these rifles are a great deal.
Bottom thickness of the gas block I have is .320". I'm going to try a VLTOR clamp type. I have one on another gun and the bottom thickness is .235".

Scope is a 2.5-10x50 Weaver Classic Extreme in a LaRue mount.
 
So does the gas block touch the rail when supported by bipod? I asked because I just ordered the same setup today.
 
So does the gas block touch the rail when supported by bipod? I asked because I just ordered the same setup today.

Very close, probably a couple of thousandths clearance. There is enough flex in the handguard that if I put a little pressure on it there is contact with the gas block.
 
You think the bottom of the gas block is thick enough that some could be filed off to help with the clearance issue?
 
The rifle looks great!

On a side note we were always taught to use torque wrenches at a 90 degree angle if we used any sort of extension. Otherwise you add length to the wrench basically providing extra leverage resulting in extra torque being applied. That being said it only adds a few lbs for something like a barrel nut adapter from what I remember from doing the calculations.
 
You think the bottom of the gas block is thick enough that some could be filed off to help with the clearance issue?

I think so and I thought about doing that myself. You'd be taking a little off the screw heads also. Still something I might try.
 
The rifle looks great!

On a side note we were always taught to use torque wrenches at a 90 degree angle if we used any sort of extension. Otherwise you add length to the wrench basically providing extra leverage resulting in extra torque being applied. That being said it only adds a few lbs for something like a barrel nut adapter from what I remember from doing the calculations.

Thanks! Brought back memories. In my other life as a jet mech I used to know the formula for finding actual torque when using an extension. I could figure it out but like you not something I'm really worried about in this application.

V/R
 
I am a helicopter electrician sometimes they let me play with torque wrenches. I do it with the 90 degree when I do it just because that is the way I was taught but glad I brought back a some fond memories! Again gorgeous rifle I cant wait to see some groups from this girl.
 
I am a helicopter electrician sometimes they let me play with torque wrenches. I do it with the 90 degree when I do it just because that is the way I was taught but glad I brought back a some fond memories! Again gorgeous rifle I cant wait to see some groups from this girl.

Well, you got me curious so I found the formula online, plugged in the numbers and came up with 49 ft lb of fastener (barrel nut) torque. Still very reasonable. Honestly, it's been so long I had forgotten the 90 degree thing. Thanks for the refresher training.. :)
 
I called my local shop, they had a troy set screw model so I think I'll just go that route. Guess ill just send the yhm gas block back. Thanks for the heads up.
 
Hand guard looks great, nice to see you post the dimensions of the gas blocks as well. I have been looking at purchasing the VLTOR gas block and was curious how small it was.
 
you have any plans of shooting some match ammo through it? Im curious how it shoots as ive heard the new SW stuff with the 5R barrels are incredibly accurate... for the prices I see those for, seems like a good deal! Wish they would do some sort of MOE or monolithic upper model though, they sure are bland in stock form, but yours came out great!
 
you have any plans of shooting some match ammo through it? Im curious how it shoots as ive heard the new SW stuff with the 5R barrels are incredibly accurate... for the prices I see those for, seems like a good deal! Wish they would do some sort of MOE or monolithic upper model though, they sure are bland in stock form, but yours came out great!

I have shot some FGGM, LC-68 Match and handloads of 168 gr Hornady Match BTHP bullets and Hornady 155 grain AMAX bullets in front of Varget. All will shoot groups of less than an inch if I do my part. That's probably about as good as I'm going to do from the prone position and with the stock trigger.

Overall I'm please with how this rifle shoots. It's a consistent MOA shooter. From a bench, with a match trigger and some load development it could only get better. Oh, maybe a little more scope too.
 
I have shot some FGGM, LC-68 Match and handloads of 168 gr Hornady Match BTHP bullets and Hornady 155 grain AMAX bullets in front of Varget. All will shoot groups of less than an inch if I do my part. That's probably about as good as I'm going to do from the prone position and with the stock trigger.

Overall I'm please with how this rifle shoots. It's a consistent MOA shooter. From a bench, with a match trigger and some load development it could only get better. Oh, maybe a little more scope too.
I stuck a Hogan drop in match trigger in my Sig 716, made the world of difference for distance. Mine liked the 168 Amax best for groups, two were touching and 1 was 1/4 inch away, with the GMM, it spread to about .75 MOA. Unfortunately at about 850m the 168s go subsonic from the 16 inch barrel so I will probably have to use the GMM for 1000m.
 
I just installed the VLTOR clamp-on low profile gas block. There looks to be plenty of clearance with the Troy TRX tube.
 
Ive been contemplating one of these myself? Looks great !!! Ive been searching for info on these but they are so new I cant find anything. Are these compatable with AR10 parts or SR25 parts ??
 
Ive been contemplating one of these myself? Looks great !!! Ive been searching for info on these but they are so new I cant find anything. Are these compatable with AR10 parts or SR25 parts ??

I've done a little research and here is what I found so far. It will take a DPMS barrel nut but the barrel extension and bolt are proprietary so barrels can't be easily swapped. I guess a guy could have a S&W barrel extension put on barrel of his choice. DPMS Low Profile handguards will match the receiver rail.

S&W says the receiver extension, bolt carrier, buffer and spring are proprietary but I have found out a couple of things. The buffer is a standard carbine buffer in length and weight. I have run a "H" carbine buffer in mine with no problems. I've read somewhere else that the receiver extension was Armalite length but have not confirmed that. The receiver extension is mil-spec diameter so most buttstocks will work. I don't know about triggers, yet.

A few thoughts about this rifle. I've owned several Armalite AR-10s, a SCAR 17s and a Colt LE901. This rifle can shoot with any of them and better than some. It is well behaved. It doesn't tear up brass too bad and will put the brass in a neat pile about 2 o'clock. It has been 100% reliable no matter what I have fed it. It is accurate with good ammo.

There are a couple of things I wish were a little different but I think S&W did a good job and I have nothing to complain about.