My 1/2MOA AR10 Build

[aaronk]

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

 

[ShooterwithNoName]

Good group, good looking rig too. I love my 308s. What kinda load did you use? Factory or hand loads?

 

[aaronk]

Good group, good looking rig too. I love my 308s. What kinda load did you use? Factory or hand loads?

Thanks! Factory 175g FGMM is pretty much all I shoot in my 308's, including for this group.

 

[Ravenworks]

Nice color.

 

[tspinaker]

Nice, I'm in the process of building one as well in 6.5 Creed.

 

[SDBguy95]

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.

 

[Dolomite_Supafly]

I seen sever X-Caliber barrels that shot extremely well. I will be ordering a few the next sale they have.

 

[TonyTheTiger]

I will be ordering a few the next sale they have.

Like right now?

 

[bfoosh006]

Impressive results.

Enjoy that precision AR.

If you are interested... a cheek pad helps with a long day of shooting... 1/16th" , 1/8th", and 1/4" thick options.
https://www.convergentdesignsolutions.com/store/p151/Cheek_Pad,_Magpul_PRS.html

 

[aaronk]

Thanks for sharing Nice grouping too, what is the final budget price on this I’m looking to go the 6.5CM route.

Bare gun with no scope or mount was just under $2300.

 

[aaronk]

Like right now?

Seems like they're never not on sale! ?

 

[TonyTheTiger]

Seems like they're never not on sale! ?

No joke, I just went and searched in my email inbox. I'm gonna hold off till the next 45% off flash sale!

 

[Dolomite_Supafly]

I'm gonna hold off till the next 45% off flash sale!

That is my plan.

 

[tspinaker]

I seen sever X-Caliber barrels that shot extremely well. I will be ordering a few the next sale they have.

How do these stack up against Bartlein or Krieger barrels? I was checking them out and the price is really good, but I'm wanting to be as accurate as possible.

 

[RTV]

That is a beautiful rifle, did you use the M5 enhanced upper for the build?

 

[aaronk]

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]

Nice build and results! How's the play/wiggle between the upper and lower for your Aero set?

 

[sam4886]

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...

 

[The DFC]

Nice looking shooter.

 

[762Armo]

Great build and accuracy.
another Washingtonian here, also in process of acquiring parts for a M5 build.
how much does your rifle weight?

 

[aaronk]

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.

 

[2aBaC̶a̶]

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.

 

[2aBaC̶a̶]

Nice build. I'm doing one similar in 6.5.

Since they fit it, I'm curious how tight does the bolt fit in the barrel?

 

[Harman117]

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?

 

[2aBaC̶a̶]

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?

No idea what brand. I can measure later when I get home.

 

[2aBaC̶a̶]

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?

The bad ones are .2720 and the good ones are .2770.

 

[bfoosh006]

The bad ones are .2720 and the good ones are .2770.

These "might" help... I have some, I could measure the OAl.

https://www.jprifles.com/buy.php?item=JPTDP-308-SET

 

[2aBaC̶a̶]

These "might" help...

https://www.jprifles.com/buy.php?item=JPTDP-308-SET

Holy shit, didn't know those existed. Thank you for that

 

[bfoosh006]

Holy shit, didn't know those existed. Thank you for that

JP makes them for AR15's as well.

The OAL might be different...I have some of both , I could measure the OAl.

 

[bfoosh006]

The bad ones are .2720 and the good ones are .2770.

I just saw on the AERO webpage... both the M5 and M5E1 use ".2795 takedown pin holes"... so YMMV.

I have a Aero M5E1 upper... and the JP oversized pins... I will slip them in tomorrow and check the fit.

 

[bfoosh006]

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.

 

[2aBaC̶a̶]

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]

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]

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]

I use 2 pieces of Medium Density Fiberboard (MDF) as vice blocks. You don't need anything fancy to assemble an upper.

 

[aaronk]

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.

308 AR10 type LR308 Upper Receiver Vise Block Tool

CNC cut NO-M.A.R® polymer protects receivers finish. Install and remove barrels that fit AR10 type flat top receivers. Universal Fit for most 308 low profile uppers. Works with bolt group and handle installed or removed. Works in bench vises that open 4 inches wide. Use horizontally to...

www.plastixrevolution.net

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

 

[C4N4DIAN]

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.

 

[762Armo]

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.

308 AR10 type LR308 Upper Receiver Vise Block Tool

CNC cut NO-M.A.R® polymer protects receivers finish. Install and remove barrels that fit AR10 type flat top receivers. Universal Fit for most 308 low profile uppers. Works with bolt group and handle installed or removed. Works in bench vises that open 4 inches wide. Use horizontally to...

www.plastixrevolution.net

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

Thanks! Appreciate the info.

 

[Johnnny13]

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]

 

[little_scrapper]

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]

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

 

[aaronk]

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! ?