replacement barrels for the M&P 10

[jrabenius]

we're not sunk.

YOU CAN replace the barrel on your M&P 10.

Those of you out there that have /are/will experience barrel failures can always send the rifle in for warranty replacement.

For those of us out there that want something different, read on.

I have heard that the DPMS barrel fits the M&P 10 receiver. I HAVE NOT TRIED THIS MYSELF, but it is a good assumption since the free float rail, hand guards, and the barrel nut threads are the same as the DPMS LR-308.

The bolt carrier group is referred to as a DPMS LR pattern.

LOTS of companies are making DPMS LR pattern bolts. They range in price from $149 to $349.

Just to give you an idea, here is what Primary Arms sells:

AR-308 Bolt Carriers | Primary Arms

There are lots of replacement barrels for the DPMS 308. Primary Arms has 2 PAGES of ar-308 barrels.

AR-308 Barrels | Primary Arms

The gas tube would also be for a DPMS LR-308, and would correspond with the barrel selected.

 

[KentB]

Very curious if anyone has assembled a DPMS barrel/BCG in the S&W upper and has success.

 

[sgtsandman]

If anyone on here has, they have not mentioned it.

 

[Drag]

I think the proprietary barrel extension that S&W utilizes on the M&P10 is the "gotcha" here. From the other threads here, I've read you can utilize a DPMS pattern barrel (and a bolt to work with it), but you'd have to refit the existing S&W extension from your M&P10's oem barrel and have a gunsmith turn the new barrel down to fit and mount the extension. This was what BHW was proposing, if I understood correctly.

I am very much interested in seeing this work, since S&W isn't very responsive with spare parts for the M&P10 let alone spare barrels.

 

[jrabenius]

(I think) you're partially right . . .

The S&W barrel extension would most likely be used if you kept the S&W bolt and bolt carrier. The S&W bolt is mated with the S&W barrel extension to provide the proper head spacing.

That's what Black Hole Weaponry was attempting.

I spoke with someone from BHW, who thinks that the DPMS bolt carrier group when used with a DPMS patterned barrel would be a drop in replacement.

 

[ghost1/6usmc]

Anyone find out for sure about the barrel swap? Any info would be greatly appreciated.

 

[Small Holes]

dpms barrel on mp10

I had the same problem, 308 barrel shot out. wanted a 6.5 creedmoor barrel so I ordered one and it doesn't fit! bummer! so, I purchased a used dpms lr308 and put my new barrel on it. shoots decent but I'm not as happy as I think i can be. the dpms has a very clunky fit between upper and lower. the mp 10 has a very tight fitting upper to lower, {I like the little rubber tits between the upper and lower that eliminates rattle and the fact that it is ambi and it is a smith&wesson!} so I purchased a new bolt to see if I can put the dpms style barrel on the mp10. the bolt is the same in every way but one, the tail end of the bolt od is .2485 on the dpms and the bolt tail on the mp10 is .310 so that creates a huge gas leak at the back of the bolt and it blows it in your face without cycling. the next step would to be to press a bushing into the bolt carrier to tighten up the gap. since I have both rifles I decided to forgo all of that and do an experiment, so I put the whole dpms bcg in the mp10 upper w the dpms barrel and viola it works great! only downside is the forward assist doesnot work anymore.but hey if you need the forward assist then you have a problem w the rifle and shouldn't shoot it anyway right? hope this helps as there is a do it yourself solution!

 

[Small Holes]

dpms barrel on mp10

so, being the perfectionist that I am, the dpms bolt carrier without forward assist just didn't set right w me. I modified the MP10 bolt carrier to fit the new nickel boron bolt. I now have a S&W MP10 with an Aero Precision 20inch 6.5 creedmoor barrel! the best part is, if I choose to go back to the original M&P barrel and bolt I can. the modification is fully reversible.

 

[WYoung]

so, being the perfectionist that I am, the dpms bolt carrier without forward assist just didn't set right w me. I modified the MP10 bolt carrier to fit the new nickel boron bolt. I now have a S&W MP10 with an Aero Precision 20inch 6.5 creedmoor barrel! the best part is, if I choose to go back to the original M&P barrel and bolt I can. the modification is fully reversible.

Great news! I wanted to try that but didn't want to sink the money if it wouldn't work.

 

[copemech]

so, being the perfectionist that I am, the dpms bolt carrier without forward assist just didn't set right w me. I modified the MP10 bolt carrier to fit the new nickel boron bolt. I now have a S&W MP10 with an Aero Precision 20inch 6.5 creedmoor barrel! the best part is, if I choose to go back to the original M&P barrel and bolt I can. the modification is fully reversible.

Great to see some confirmation on this issue. Can you tell why the FA does not function or does the bolt simply not have the serrations cut?

How did you mod the bolt carrier? A bushing? I ran this across my feeble grey matter and wondered what would keep that from blowing out?

 

[Small Holes]

the mp10 bolt has serrations in the bolt carrier and the pusher is mounted toward the rear of the upper. the dpms has the pusher located more towards the front of the upper, with a single ridge toward the front of the bcg that the pusher pushes on. the hole in the rear of bcg piston chamber is measured and a bushing is turned on a lathe to be a .003 interference fit. it is pressed in the bcg with a 5 ton arbor press, its very tight! the bgc is put into a 15/16 collet chuck on the lathe and the bushing where the bolt tail goes into the bcg is reamed w a .252 reamer. ive got 300 rounds down the pipe now with no issues. the rifle with its new Ballistic Advantage 6.5 creedmoor barrel now shoots just under 1/2 in. groups with Hornady 140ELD match ammo with no muzzle brake and little recoil, as opposed to 1 1/2 - 3 in. groups w factory barrel and 168g match 308.

 

[Drag]

This is GREAT news! This was my next attempt - just swapping out the barrel and bolt completely. Excellent to hear that it works.

 

[bergermeister]

Congratulations (on cracking the 'nut')

so, being the perfectionist that I am, the dpms bolt carrier without forward assist just didn't set right w me. I modified the MP10 bolt carrier to fit the new nickel boron bolt. I now have a S&W MP10 with an Aero Precision 20inch 6.5 creedmoor barrel! the best part is, if I choose to go back to the original M&P barrel and bolt I can. the modification is fully reversible.

I assume to make it "reversible" you press the bushing out, even though I cannot understand why someone would want to go back to the proprietary barrel/extension..
Good skull-work!

 

[4mer03e5]

hbar option for M&P 10

Is there a 20-24" HBAR that will fit "our" rifles? I would think a longer heavy barrel floated upper would be a great start to a serious tack-driver. Just looking for opinions and guidance on this. I may seek the camo/HBAR m&p 10 to mod out. My scoped/"stock" m&p 10 is great just looking at options and opinions. Thanks in advance and Semper Fidelis!!!

 

[arroyoshark]

I wonder if a machine shop could cut the rearward serrations on a DPMS bolt carrier such that the S&W forward assist might then engage and work with the DPMS bolt?

That might prove to be the best of all worlds.

 

[Small Holes]

jp enterprises bcg has em

 

[arroyoshark]

jp enterprises bcg has em

As soon as I submitted my reply, I had one of those "duh" moments. Primary Arms sells DPMS pattern bolt carriers and bolts.

I find it a revelation that such a barrel/bolt carrier group swap puts the M&P 10 back on par with most other DPMS based AR10's. My barrel is not shot out, but the potential to switch to another caliber when the time comes is intriguing. The .243 Win. round has always interested me and might be fun in an AR platform.

I find it somewhat incredulous that S&W determined it had to take a difficult path to their M&P10's, tho I must say they seem to run really nicely.

Thank you for your contribution to this thread and body of knowledge.

 

[Gischileu]

jp enterprises bcg has em

So, if I'm following you here, a DPMS pattern barrel with any decent DPMS pattern AR308 BCG should be a complete match without the need for machine work? I was looking specifically at the Aero Precision Nickel Boron BCG - which does have the forward assist grooves along the side of the BCG.

 

[Small Holes]

aero p wont work. dpms pattern only

 

[Gischileu]

Small Holes:

This is the Aero Precision Nickel Boron BCG at Primary arms - their description says its a DPMS patterm BCG. Am I missing something else here?

Aero Precision .308 Complete Bolt Carrier Group - Nickel Boron - APRH100185