6mm ARC Thread

[PappyM3]

6 MAX seems like an interesting option if you want to stay with a standard AR15 bolt face, but you lose the ability to use the top end, heavier high BC bullets like Berger Hybrid 105's and 109's. The body of the case is long and the neck seems a bit short. You only go from the 34 grains water capacity to 35 grains water capacity from the 6 ARC to the 6 MAX, so the velocity gain isn't much. Shorter, fatter cases with long necks are better for accuracy. Take a look at the 6 BR, 6 GT, 6 XC etc. and compare those against the 6 ARC and 6 MAX cases. The 6 ARC is more akin to those cartridge cases.

A quote from Brian Cook at 6mmMAX.net -

Wondering about accuracy? On Aug 6th, 2022, I competed with the 6mm MAX in F-Class with my local club the Central Texas Silhouette Association or CTSA. Full disclosure on me? I’m an old F-Open High Master. My normal competition gun is a .243 30” Bartlein barrel running 105 hybrids at 3050 fps with a stout load of H4831SC. The 6mm MAX is not a competitive F-Open cartridge by any stretch of the imagination, but I wanted to see an actual real world test of accuracy in the hot south Texas switching winds at 500 yards. I used a 24” Bartlein barreled hunting rig. This is the same bolt rifle pictured on this web site. It has 2600 rounds of testing down range, and is till holding sub-MOA with a load of H4895 tested to SAAMI standards of 53,000 psi. The load was 26.6 grs of H4895, and 90 gr Lapua Scenar-L at 2.30 OAL. This load was straight from our loading chart on this web site. After the 3rd relay my score was 568-6X. Nothing to write home about by F-Class standards, but in the world of hunting and rifle accuracy these rounds would have HARVESTED GAME.

So if I were building an AR16 strictly for hunting varmints, 6 MAX might be the better option. The initial feedback on Sniper's Hide is that the 6 MAX is a varmint round. For long distance accuracy I'm better off with the 6 ARC. Cold bore groups below .5 MOA are no joke from any rifle, but especially from an AR. If you are running 6.5 Grendel, you already have the right bolt for 6 ARC.

They have had a sponsored shooter winning Quantified Performance matches with 6 Max. I feel like trying to compare it to F-Class is a little silly, as it’s definitely not the purpose. It’s clearly meant for gas guns.

I feel like 6 Max would be a great option to upgrade a standard duty rifle. Instead of the 6.8 SPC, if 6 Max was attempted instead, I think it would have been a great 5.56 replacement. New mags and barrel. And nowadays if they created a 100 gr M855A1 style tipped boat tail bullet, “muah, chef’s kiss”. The caveat is that in order for most to switch, it would have had to have been mass-adopted by the DoD.

But as a specialty round in addition to having 5.56, 6 ARC seems like a better proposition to shoot those 105s/108s.

 

[Mountain]

Some very active threads on SnipersHide including lots of builds including some by pros: Lets see your 6 ARC build

Just sharing that as evidence that the caliber seems to have staying power in the community.

 

[BD1]

I just joined NES, I found it searching for 6mm ARC load data, which turned up this thread. Interesting reading. I just finished building a dedicated target upper: Vltor receiver, Craddock 22" RTR barrel with Craddock headspace JP bolt and a wide body handguard. I ordered some 105 Scenars as they were available and managed to luck into a box, (last one) of the Berger 109 hybrids when they were in stock for about 10 minutes while I was making the order. Now I just need the road into the range to dry up enough to drive on. This is my third AR build and I'm planning to use this on my old high power lower as I'm very used to that stock and trigger. I've been competing locally with a WOA 24" truck axle upper in .223, (a 1/4 MOA setup), and doing OK, but I lose to the creedmores and .308s on the gusty windy days. I'm hoping the ARC will help address that.

 

[Mountain]

I just joined NES, I found it searching for 6mm ARC load data, which turned up this thread. Interesting reading. I just finished building a dedicated target upper: Vltor receiver, Craddock 22" RTR barrel with Craddock headspace JP bolt and a wide body handguard. I ordered some 105 Scenars as they were available and managed to luck into a box, (last one) of the Berger 109 hybrids when they were in stock for about 10 minutes while I was making the order. Now I just need the road into the range to dry up enough to drive on. This is my third AR build and I'm planning to use this on my old high power lower as I'm very used to that stock and trigger. I've been competing locally with a WOA 24" truck axle upper in .223, (a 1/4 MOA setup), and doing OK, but I lose to the creedmores and .308s on the gusty windy days. I'm hoping the ARC will help address that.

Sounds like a great build and welcome to the forum.

Those scenars are Lapua? I'm curious how they'll run for you. All the ELD's / VLD's etc had way too much jump for me at mag length. So far the 105 Hybrids and 105 BT Targets have been my go-to.

 

[BD1]

Sounds like a great build and welcome to the forum.

Those scenars are Lapua? I'm curious how they'll run for you. All the ELD's / VLD's etc had way too much jump for me at mag length. So far the 105 Hybrids and 105 BT Targets have been my go-to.

Yes, the Scenars are Lapua. I'll let you know. The mags I have look like they would allow 2.34 OAL. But it's hard to say without trying them. I tried to make a OAL gauge modified case this afternoon without any luck, and I've made five or six of them. The case is too short, and lacks taper to secure it in an oak block to drill it out so I ordered one from Midway.

 

[Mountain]

Yes, the Scenars are Lapua. I'll let you know. The mags I have look like they would allow 2.34 OAL. But it's hard to say without trying them. I tried to make a OAL gauge modified case this afternoon without any luck, and I've made five or six of them. The case is too short, and lacks taper to secure it in an oak block to drill it out so I ordered one from Midway.

I've run the scenars in military matches. Excellent bullet and very, very consistent. Not sure they have quite the BC as Berger Hybrids but should be better than the BC for Berger Target BT's.