My 1/2MOA AR10 Build

aaronk

Private
Minuteman
Jan 21, 2018
70
56
24
Washington
Been wanting to build an AR10 for a while, but kept putting it off given what I'd read about the sub-par accuracy and finicky nature of them. Given some changes in WA state law surrounding buying AR platform rifles I bit the bullet and bought a stripped upper and lower and decided to start piecing one together - 6 months later and a robbed scope from my bolt gun and it's finally done 😂

I've gotta say, this build surpassed my expectation as to what I thought I could reasonably attain accuracy wise. To say I'm happy with it is putting it mildly! I was a little hesitant going with an X-Caliber based on some of the mixed reviews I've read, but it seems like the poor ones were from a while ago. I did send them my JP bolt to headspace the chamber off of. They guarantee 1moa accuracy if you do this.

Build details:

Aero M5 308 upper and lower
Aero M5 enhanced Gen 2 M-Lok handguard
Aero parts kits for the upper and lower
Magpul PRS stock
CMC 2-stage trigger
Area 419 Arca Rail
JP Enterprises HP bolt
JP Enterprises full mass BCG
JP Enterprises silent capture H2 buffer
X-Caliber 416R stainless 18" 10 twist 5R socom heavy profile
Rifle length gas system with Superlative adjustable gas block

IMG_9682.jpg

IMG_9681.jpg
 

Cy Rosenlund

Private
Minuteman
Apr 6, 2019
37
28
24
Thats a nice unit, and nice group! I built one alot like that one in 6.5 creedmoor. Loved the looks and lack of recoil, but couldnt get over how heavy it was. Felt like I was carrying a green treated 4x4 every time I picked it up.
 
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RTV

Rock the Vote
Minuteman
Nov 30, 2019
51
17
12
That is a beautiful rifle, did you use the M5 enhanced upper for the build?
 

aaronk

Private
Minuteman
Jan 21, 2018
70
56
24
Washington
That is a beautiful rifle, did you use the M5 enhanced upper for the build?
Thanks! No, standard M5 upper. They didn't offer the M5 Enhanced in a builder's set that I could find. I was a little worried about timing the barrel nut as this was my first time building an AR upper, but it was pretty simple.
 

Harman117

Private
Minuteman
Feb 2, 2018
75
59
24
Ohio
Nice build and results! How's the play/wiggle between the upper and lower for your Aero set?
 

sam4886

Double tap
Belligerents
Minuteman
May 15, 2019
316
137
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Columbia basin
The aero lowers have a set screw kinda thing that snugs up the rear take down lug to take the wiggle out. They're pretty effective.

You've got me inspired to build on the m5 lower I bought a while ago. I'm in WA too, so it was probably bought at the same time. I blew a big was on my last ar15 build so I've been trying to ignore the large frame sitting in the safe. Still have half a g20 to build too...
 

762Armo

Private
Minuteman
Dec 5, 2019
3
1
6
Great build and accuracy.
another Washingtonian here, also in process of acquiring parts for a M5 build.
how much does your rifle weight?
 
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aaronk

Private
Minuteman
Jan 21, 2018
70
56
24
Washington
Nice build and results! How's the play/wiggle between the upper and lower for your Aero set?
Thanks! No better or worse then any of the AR15's I've owned, which have been complete BCM's or BCM uppers on Aero lowers.

Great build and accuracy.
another Washingtonian here, also in process of acquiring parts for a M5 build.
how much does your rifle weight?
On the bathroom scale with bipod and unloaded mag it's 15.4 lbs.
 

2aBaCa

Major Hide Member
Belligerents
Minuteman
Jan 27, 2019
1,390
1,101
119
Behind enemy lines Northern Commiefornia
Nice build and results! How's the play/wiggle between the upper and lower for your Aero set?
The aero lowers have a set screw kinda thing that snugs up the rear take down lug to take the wiggle out. They're pretty effective.

You've got me inspired to build on the m5 lower I bought a while ago. I'm in WA too, so it was probably bought at the same time. I blew a big was on my last ar15 build so I've been trying to ignore the large frame sitting in the safe. Still have half a g20 to build too...
As a side note. I have a M5E set and fit is snug "IF" i use the right takedown pins. I had a problem with a first set of pins that were undersized by a couple thou and made the fit sloppy.

While the screw mentioned above did tighten when the undersized pins were in, it pushed the rear of the reciever set apart which bothered me and made the rear takedown pin difficult to open. Once I changed to the right set of takedown pins everything worked flawless.

One of my sig lowers has the similar screw but it is spring loaded so it applies pressure when closed.
 

Harman117

Private
Minuteman
Feb 2, 2018
75
59
24
Ohio
As a side note. I have a M5E set and fit is snug "IF" i use the right takedown pins. I had a problem with a first set of pins that were undersized by a couple thou and made the fit sloppy.

While the screw mentioned above did tighten when the undersized pins were in, it pushed the rear of the reciever set apart which bothered me and made the rear takedown pin difficult to open. Once I changed to the right set of takedown pins everything worked flawless.

One of my sig lowers has the similar screw but it is spring loaded so it applies pressure when closed.
Do you remember what brand/type/dimension of takedown pins you used for the snug fit? I have read before to use the ones Aero makes for the M5, are those it?
 

bfoosh006

Sergeant
Belligerents
Jun 13, 2007
731
226
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PNW
Holy shit, didn't know those existed. Thank you for that
I was easily able to find the JP 308 Oversized ones.... they measure .279 - slightly under at the shank... .279 + slightly at the tip.
The heads are stouter... and interestingly, the front pivot pin was a snug fit in the Aero and PSA's uppers ... the rear pin was looser fitting in the Aero then the PSA rear hole.

So I'd do the front first , try the snug fit ... then do the rear as needed.

And for what its worth... KNS Precision Fit 308 take down pins were both ( front and back ) .2773 ish ( slightly past the .277 )

Measure yours first... the holes on the upper and lower may be a little quirky ... Lol, as in not a 100% bore aligned.
 

2aBaCa

Major Hide Member
Belligerents
Minuteman
Jan 27, 2019
1,390
1,101
119
Behind enemy lines Northern Commiefornia
I'm good now, the loose pair I found in my spare parts bin fits snug. I never really paid much attention to the actual sizes. Good to know there are different ones out there and that it really tightens up the fitment of the receivers.
 

762Armo

Private
Minuteman
Dec 5, 2019
3
1
6
Aaronk,
Which vise block did you use to hold the upper in place to torque down the barrel?
Which barrel wrench/armorers tool did you use?
This is my first build, and I don't have any AR specific tools yet, read that some don't work with the M5?...

Thank you,
 

Mk32784

Private
Belligerents
Minuteman
Aug 1, 2017
212
102
49
Aaronk,
Which vise block did you use to hold the upper in place to torque down the barrel?
Which barrel wrench/armorers tool did you use?
This is my first build, and I don't have any AR specific tools yet, read that some don't work with the M5?...

Thank you,
I use a Geissele reaction rod to build my Aero M5 setup.
 

Merle

Maestro Sarge
Belligerents
Jan 13, 2010
160
53
34
43
Phoenix, AZ
I use 2 pieces of Medium Density Fiberboard (MDF) as vice blocks. You don't need anything fancy to assemble an upper.
 

aaronk

Private
Minuteman
Jan 21, 2018
70
56
24
Washington
Aaronk,
Which vise block did you use to hold the upper in place to torque down the barrel?
Which barrel wrench/armorers tool did you use?
This is my first build, and I don't have any AR specific tools yet, read that some don't work with the M5?...

Thank you,
I used the PlastiXrevolution upper vice block and was very happy with it. I also picked up their lower vice block as well for the castle nut installation.

Used a standard Magpul Armorer's Wrench for barrel installation and castle nut.
 

C4N4DIAN

Sergeant of the Hide
Belligerents
Minuteman
Aug 16, 2019
108
45
34
Been wanting to build an AR10 for a while, but kept putting it off given what I'd read about the sub-par accuracy and finicky nature of them. Given some changes in WA state law surrounding buying AR platform rifles I bit the bullet and bought a stripped upper and lower and decided to start piecing one together - 6 months later and a robbed scope from my bolt gun and it's finally done 😂

I've gotta say, this build surpassed my expectation as to what I thought I could reasonably attain accuracy wise. To say I'm happy with it is putting it mildly! I was a little hesitant going with an X-Caliber based on some of the mixed reviews I've read, but it seems like the poor ones were from a while ago. I did send them my JP bolt to headspace the chamber off of. They guarantee 1moa accuracy if you do this.

Build details:

Aero M5 308 upper and lower
Aero M5 enhanced Gen 2 M-Lok handguard
Aero parts kits for the upper and lower
Magpul PRS stock
CMC 2-stage trigger
Area 419 Arca Rail
JP Enterprises HP bolt
JP Enterprises full mass BCG
JP Enterprises silent capture H2 buffer
X-Caliber 416R stainless 18" 10 twist 5R socom heavy profile
Rifle length gas system with Superlative adjustable gas block

View attachment 7189641

View attachment 7189640
this is a sick build ! thanks for sharing.
 
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762Armo

Private
Minuteman
Dec 5, 2019
3
1
6
I used the PlastiXrevolution upper vice block and was very happy with it. I also picked up their lower vice block as well for the castle nut installation.

Used a standard Magpul Armorer's Wrench for barrel installation and castle nut.
Thanks! Appreciate the info.
 

Johnnny13

Sergeant
Belligerents
Jan 24, 2013
110
4
22
Texas
Build details:

Aero M5 308 upper and lower
Aero M5 enhanced Gen 2 M-Lok handguard
Aero parts kits for the upper and lower
Magpul PRS stock
CMC 2-stage trigger
Area 419 Arca Rail
JP Enterprises HP bolt
JP Enterprises full mass BCG
JP Enterprises silent capture H2 buffer
X-Caliber 416R stainless 18" 10 twist 5R socom heavy profile
Rifle length gas system with Superlative adjustable gas block

Awesome job on the build. I will Be replicating this, minus the barrel, in few months.


[/QUOTE]
 
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little_scrapper

Sergeant of the Hide
Belligerents
Minuteman
May 31, 2019
208
104
49
Great group. I still want to see a 5x x 5x group on same page. All filmed in one consecutive take with todays newspaper in view the whole time. Otherwise its just 1 MOA so far.

LOL
 

wildcats

Sergeant
Belligerents
Mar 26, 2005
955
538
219
Honolulu,HI
Goes to show that you don't have to spend 4k on an AR-10 to achieve excellent accuracy.
It will probably group even better with handloads
 
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aaronk

Private
Minuteman
Jan 21, 2018
70
56
24
Washington
Great group. I still want to see a 5x x 5x group on same page. All filmed in one consecutive take with todays newspaper in view the whole time. Otherwise its just 1 MOA so far.

LOL
Left the crop bigger and the dime for scale off the picture so no one would claim any funny business! 😂