Lets see your 6 ARC build

I am still waiting on the Geissele SD-E trigger and for my AAC SDN-6 to get back from Echo Machine for the HUB conversion, but other than that the 6 ARC is done.

  • LMT MARS- L MRP
  • Proof Research Carbon 18" 6 ARC barrel 1:7.5 twist Rifle +1, D. Wilson LMT Barrel conversion w/SLR Micro Gas Block
  • Rearden SPB .375/HUB
  • JP Enterprises 6mm ARC Bolt
  • Night Force ATACR 4-16x42 Mil-XT
  • Reptilia AUS 34mm 0 moa

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Built mine from scrap parts of other builds minus the barrel and handguard. I'm still thinking about adding a vertical grip to it and I haven't decided on a scope yet though I'm checking out the Optika 6 from Europtic since they're on sale right now. Will probably finish off with a Griffin Paladin brake and 15 MOA GPM mount since they are local to me. Might also swap the trigger for a Calvin Elite eventually but I didn't have one lying around and I didn't see any decent sales on them.

Parts List:
Rainier Arms Match Barrel 6 arc 7.5 twist 22" barrel
SgtOfArms ARCA 18" handguard
Aero Precision enhanced M4E1 upper
Magpul PRS Lite stock
Ergo Beavertail pistol grip
Anderson Lower
Rise Armament trigger

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How has that barrel treated you?
 
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It actually fits this rifle’s use well - purely long range low recoil steel shooting. Took it out to around 1400 yards even. But it’s pretty unwieldy and because I really like the cartridge, I have a 16” Proof carbon barrel getting fitted to one of my LMT MLRs. I’m going to bracket the barrel length on this cartridge like I’m bracketing mortars.
 
How has that barrel treated you?
The jury is still out. So far the Precision Hunter ammo has been sub-moa, but it really doesn't like Hornady Black 105's lol. Probably around 2 moa with that so far. I'm just using it to get some brass so I can see if Varget or CFE223 makes a good powder for it.
 
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Nothing particularly special about this one other than the Bartlein barrel, matched JP high pressure bolt, and Geissele trigger-

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So far my best load (below) gets sub 0.5 MOA cold bore groups and ~0.4 MOA groups overall. SD is 4, ES is 11.

(edit- Must have forgotten to post load?)

Berger 105 BT's and Hybrids are giving similar great groups, Starline brass. I'm running 2520 well within Accurate/Hodgdon limits. The load does slightly exceed Hornady 'semi' limits, so I don't recommend to others and if you do tread there be sure to have top notch bolt like the JP high pressure or a Wilson Combat. That said, there are zero signs of pressure and I have several loads on the same batch of brass with no failures.

At least the lots of Hornady factory ammo I have shot have flattened primers and I've seen one slightly loose primer pocket upon reload. They appear to be loaded quite hot for a factory load, which seems contradictory to their very conservative load data for semi's. In the above rifle, Hornady Black shoots 1.5 MOA at best.
 
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I don't know why everyone hates on the exposed gas block aesthetic. On the right gun it looks pretty cool. Some people act like it'll get knocked around, like an A2 FSB wouldn't?

I don't have any issues with it, gives it a Mk12 look. I am more concerned about the gas system at the moment than aesthetics.
 
One of my personal 6 arc builds.

12" barrel I spun up myself, LMT Specwar upper, shorty PDW stock. Have since switched to an RC3 suppressor.

Managed to get some hits at 1,000 yards over the weekend.

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Which carrier and bolt? Thoughts on the RC3? And what's the story with bottom side of the lower rail?
 
Which carrier and bolt? Thoughts on the RC3? And what's the story with bottom side of the lower rail?

Centurion sandcutter carrier, JP bolt

I'll preface by saying a 556 RC3 is definitely not meant to fit a 6mm projectile, but after some very thorough alignment checks and making a custom muzzle device, I got it to work. It had very little back pressure which is nice.

The bottom side of the rail are some bolt on ARCA adapters I came up with since I don't like the clunky one piece plates.
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Did my first 6 ARC build this spring. Easy to shoot...had to make it look different than my 6.5G so I don't grab the wrong rifle and ammo. (Wade did not influence me in doing a "taninized" build...lol)

Geissele SD Lower
TT Diamond Trigger
Proof Carbon 18"
SA Adjustable Gas Block
SilencerCo GDCH (reduce gas)
Gemtech suppressed BCG
JP Bolt
BCM MCMR hand guard
Geissele Mount/NF NX8 2-20
VLTOR A5 Buffer

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This one is for me: 18" Proof CF barrel hosted by a Rogue Ops Builder's Kit. Young Mfg. N/M bolt carrier and JP bolt, SLR adjustable gas block, TriggerTech Diamond trigger, BCM MK 2 recoil system, NF ATACR 4-16x42 F1 w/ T3 reticle in Spuhr mount, CGS Helios QD-Ti can.

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Beautiful rifle! How is the back pressure on the cgs helios with 6 ARC? Direct thread?
 
Beautiful rifle! How is the back pressure on the cgs helios with 6 ARC? Direct thread?
Thank you, sir!

Yes, 100% direct thread.

I'm currently running the CGS with the open end cap. No discernible back pressure but a little sharp in the sound department. The gun runs very clean.

With the closed end cap, it is much quieter, and the gas really isn't bad at all. But the powder/s Hornady is using gets pretty messy.
 
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6ARC build evolution step 3 - diving board mounted LAM proof of concept worked, so replaced with Mars-c, and since no more MAWL up front, no more Unity riser for clip-on and high rings. Going to find out tomorrow night whether this thing fucks or not.
 
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Here's a rough draft of my 6ARC SBR, still waiting on the 14.5" Bartlein from Paul Ross. Right now I'm using a 14.5" Craddock RTR 6ARC as a placeholder.

Once the Bartlein comes in I'll send it in for the Cobalt kinetics green cerakote.

Here the finally build specs.

Larue OBE Receiver Set

Paul Ross 14.5" Bartlein / 4 Groove / 1-7.5 Twist / Knights Armament Mid Length 13" Gas System / Straight Taper Contour .800 Gas Block Journal, step down to .780 to the muzzle.

TriggerTech 3.5lb 2 stage Duty Trigger.

Young Manufacturing 6mm ARC Chrome BCG w/ HMB Bolt.

JP H2 SCS .

SA .800 AGB.

B5 Precision stock.

Dark Hour 11 position Receiver Extension.

Radian Raptor SD Ambidextrous Charging Handle.

MagPul MOE K2-XL GRIP

Dedicated Dead Air Lazarus 6 Suppressor.

So far the Craddock RTR barrel has shown to be decently accurate with the Hornady Ammo Options.

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Here's a rough draft of my 6ARC SBR, still waiting on the 14.5" Bartlein from Paul Ross. Right now I'm using a 14.5" Craddock RTR 6ARC as a placeholder.

Once the Bartlein comes in I'll send it in for the Cobalt kinetics green cerakote.

Here the finally build specs.

Larue OBE Receiver Set

Paul Ross 14.5" Bartlein / 4 Groove / 1-7.5 Twist / Knights Armament Mid Length 13" Gas System / Straight Taper Contour .800 Gas Block Journal, step down to .780 to the muzzle.

TriggerTech 3.5lb 2 stage Duty Trigger.

Young Manufacturing 6mm ARC Chrome BCG w/ HMB Bolt.

JP H2 SCS .

SA .800 AGB.

B5 Precision stock.

Dark Hour 11 position Receiver Extension.

Radian Raptor SD Ambidextrous Charging Handle.

MagPul MOE K2-XL GRIP

Dedicated Dead Air Lazarus 6 Suppressor.

So far the Craddock RTR barrel has shown to be decently accurate with the Hornady Ammo Options.

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Loving my 14.7" RTR right now too, but hope it speeds up some over the next couple hundred rounds. It shot 80's right at MOA for 5 shot groups but the 3 shots were way smaller (these bullets seem to be a little finicky but great BC).

Running a MK5 2-10 for clip on use and it's been perfect. How do you like the new DA can?
 
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Loving my 14.7" RTR right now too, but hope it speeds up some over the next couple hundred rounds. It shot 80's right at MOA for 5 shot groups but the 3 shots were way smaller (these bullets seem to be a little finicky but great BC).

Running a MK5 2-10 for clip on use and it's been perfect. How do you like the new DA can?

Mine doesn't seem to like the 80's, loves the 108's.

Here is the 80 VT
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