Aero DMR upper build in 6mm arc

[Shadow9mm]

So I think I'm getting close enough now to share this. I got most of my parts in, and the upper mostly together today, still waiting on a part or 2. Been wanting to do a target/DMR build for a while now. Another forum member gave me a good deal on a 6mm ARC barrle, BCG and a few other assorted items he decided to go another direction with his build. I decided to to go all aero for the build just because I could.

20in stainless DMR barrel in 6mm ARC from Ballistic advantage (partnered with Aero, makes their in house barrels I believe)
Aero standard upper
Aero adjustable gas block
Aero stainles gas tube
Aero 6.5 grendel (type 2) BCG
Aero 15in Atlas R-ONE handguard cerakoted in Magpul OD green.

I did get a set of 6mm arc go/no-go gauges, Barrel and BCG passed without issue. Also got a duramag SS for 6.5 grendel/6mm arc.

I have ordered but am still waiting on my muzzle device, a Kaw Valley Mach 3 linear compensator with a flash hider end cap. Hoping to use only 1 section to keep the length down.

Really been looking forward to loading for and shooting this build. Should be a ton of fun. Ill keep you posted on how she does.

[rickyrick]

Looking good!

I want to try one of those fat-cartridge builds one day.

[Shadow9mm]

Range Report!

First range outing today. Put 90rns of factory ammo through her. 40rns of Hornady match with the 108g ELD-m bullet as well as 50rnds of hornady Black with the 105g open tip match bullet.

To be honest I left half a box of black on the kitchen table by accident, I had already loaded 10rnds into the mag. I do plan to start loading for it soon, but I am somewhat glad I have 1 mag of factory ammo left.

I started out zeroing the gun at 25yds. My plan was to tune the Aero adjustable gas block at the same time. However I found it needed no adjustment as it was kicking round at at 3:30 perfectly the whole time. The lower currently has a H buffer with a Spingco blue (+15%) spring in it.

Accuracy: Before I start throwing numbers out, accuracy was poor today. Best group was 1.23moa at 100yds. However I am attributing this to an equipment problem. I had installed a Kaw Valley Mach 3 linear compensator. This is a modular system with sections that can be added and removed to adjust the over all length. I had applied frog lube paste to the threads of the sections in the hopes of preventing it seizing up with carbon fouling and tightened it firmly. At the end of the session while putting the gun up I found it to have loosened in a couple places. At this point I am attributing the accuracy issues to it coming loose. When I got home I took it apart, stripped the oils, added a generous amount of Rocksett to the threads and again tightened the sections together firmly. Hopefully this solves the problem.

Magazine: I had read a number of people had issues with feeding and magazine. While my sample size is 1 at this point mine ran flawlessly. It is a 10rnd Duramag SS (stainless) for 6.5 Grendel.

Chronograph: I put 20rnds of each ammunition over the chronograph. Not all rounds were recorded due to some technical issues and a bit of a learning curve with a new brand of chrono. Chrono was set up at 15ft from the muzzle which I believe is Saami spec if I remember right.

Keep in mind I have a 20in barrel. The match ammo stated they used a 24in BBL. the Black did not list a barrel length, however seeing at the bullet weights are similar and are both listed on the box as 2750 Id say its highly likely.

Hornady Black 105g Open Tip Match
20 shots recorded
Avg 2613 fps
ES 39 fps
SD 12 fps

Hornady Match 108g ELD-M
18 shots recorded
Avg 2560 fps
ES 83 fps
SD 22 fps

Side note, Hoping to have the full build done in about 2 weeks or so. Have all the parts now except the trigger. I am still debating between Elftman, Trigger Tech, and Jard. Leaning heavily towards the Elftman as you can take it apart to clean it yourself if you had to, and bearing are cool!

[jetinteriorguy]

Originally Posted by Shadow9mm

Range Report!

First range outing today. Put 90rns of factory ammo through her. 40rns of Hornady match with the 108g ELD-m bullet as well as 50rnds of hornady Black with the 105g open tip match bullet.

To be honest I left half a box of black on the kitchen table by accident, I had already loaded 10rnds into the mag. I do plan to start loading for it soon, but I am somewhat glad I have 1 mag of factory ammo left.

I started out zeroing the gun at 25yds. My plan was to tune the Aero adjustable gas block at the same time. However I found it needed no adjustment as it was kicking round at at 3:30 perfectly the whole time. The lower currently has a H buffer with a Spingco blue (+15%) spring in it.

Accuracy: Before I start throwing numbers out, accuracy was poor today. Best group was 1.23moa at 100yds. However I am attributing this to an equipment problem. I had installed a Kaw Valley Mach 3 linear compensator. This is a modular system with sections that can be added and removed to adjust the over all length. I had applied frog lube paste to the threads of the sections in the hopes of preventing it seizing up with carbon fouling and tightened it firmly. At the end of the session while putting the gun up I found it to have loosened in a couple places. At this point I am attributing the accuracy issues to it coming loose. When I got home I took it apart, stripped the oils, added a generous amount of Rocksett to the threads and again tightened the sections together firmly. Hopefully this solves the problem.

Magazine: I had read a number of people had issues with feeding and magazine. While my sample size is 1 at this point mine ran flawlessly. It is a 10rnd Duramag SS (stainless) for 6.5 Grendel.

Chronograph: I put 20rnds of each ammunition over the chronograph. Not all rounds were recorded due to some technical issues and a bit of a learning curve with a new brand of chrono. Chrono was set up at 15ft from the muzzle which I believe is Saami spec if I remember right.

Keep in mind I have a 20in barrel. The match ammo stated they used a 24in BBL. the Black did not list a barrel length, however seeing at the bullet weights are similar and are both listed on the box as 2750 Id say its highly likely.

Hornady Black 105g Open Tip Match
20 shots recorded
Avg 2613 fps
ES 39 fps
SD 12 fps

Hornady Match 108g ELD-M
18 shots recorded
Avg 2560 fps
ES 83 fps
SD 22 fps

Side note, Hoping to have the full build done in about 2 weeks or so. Have all the parts now except the trigger. I am still debating between Elftman, Trigger Tech, and Jard. Leaning heavily towards the Elftman as you can take it apart to clean it yourself if you had to, and bearing are cool!

Definitely go with the Elftman trigger. I now have them in all my AR’s and absolutely love them.

[USAF Ret]

Great report. Waiting for the next one and hoping for good results.