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.

 

[Mountain]

Been a minute since I posted in this thread. Guess who's the latest to take a drink of the 6mm ARC Koolaid? Mike shows how well it shoots out to 1,000 yards in windy conditions.



IIRC he was shooting some factory ammo that I'm not a fan of and for sure I'm getting way better downrange results with my pet load of 29.0 grains 2520 generating 2739 fps avg with Berger 105's, SD ~4, ES 11, and running ~51,000 psi.

Anyway, with a strong endorsement from Garand Thumb this cartridge is going to see that much more exposure and will likely continue to gain in popularity.

 

[LakeTrout]

I saw that and thought it was really cool. Is brass more available than it used to be? That was holding me back.

 

[Mountain]

I saw that and thought it was really cool. Is brass more available than it used to be? That was holding me back.

There are a number of the bigger retailers as well as some highly rated small shops with 6 ARC brass in stock. It's backordered at Starline direct, but many of the distributors with stock have pricing similar to Starline's direct price.

 

[PappyM3]

I was looking around at mag options and stumbled across this.



Who’s spending $70 on an 8-round mag?

5 round, I get.
10 round, I get.
Random amounts over 10 to maintain reliability, like 12 or 17, I get.

But 8? Surely they can make a reliable 10 rounder. Even if it takes making a new magazine body; for $70 that should be on the table.

 

[phidelt208]

I can tell you I sure like my 6 arc, it's a really really great cartridge for a gas gun. Probably better cartridges for bolt guns but it wasn't designed for that.
Flat, shooting, light and accurate if you get a good enough barrel.

 

[phidelt208]

I was looking around at mag options and stumbled across this.

View attachment 909122

Who’s spending $70 on an 8-round mag?

5 round, I get.
10 round, I get.
Random amounts over 10 to maintain reliability, like 12 or 17, I get.

But 8? Surely they can make a reliable 10 rounder. Even if it takes making a new magazine body; for $70 that should be on the table.

I definitely wouldn't pay $70 for that magazine. To each his own, I'm sure there are people desperate enough to buy it.

 

[paul73]

I was looking around at mag options and stumbled across this.

View attachment 909122

Who’s spending $70 on an 8-round mag?

5 round, I get.
10 round, I get.
Random amounts over 10 to maintain reliability, like 12 or 17, I get.

But 8? Surely they can make a reliable 10 rounder. Even if it takes making a new magazine body; for $70 that should be on the table.

i do see 6 arc as a very interesting toy, but i am totally lost of WHY i would need one, at all.
and its brass, the whole idea of the .223 AR is to shoot it at will and never bend over to pick up damn cases. when brass goes at close to a $1 a pop, it will be one damn grass combing exercise an every time you pull a trigger...

and .308 is still cheaper.

 

[M1911]

i do see 6 arc as a very interesting toy, but i am totally lost of WHY i would need one, at all.
and its brass, the whole idea of the .223 AR is to shoot it at will and never bend over to pick up damn cases. when brass goes at close to a $1 a pop, it will be one damn grass combing exercise an every time you pull a trigger...

and .308 is still cheaper.

A 308 AR is much bigger and heavier. I believe a 6mm ARC AR is the same size as a 5.56 but with far better ballistic performance at longer ranges.

 

[50wt]

i do see 6 arc as a very interesting toy, but i am totally lost of WHY i would need one, at all.
and its brass, the whole idea of the .223 AR is to shoot it at will and never bend over to pick up damn cases. when brass goes at close to a $1 a pop, it will be one damn grass combing exercise an every time you pull a trigger...

and .308 is still cheaper.

Because 6mm bullets are better. Low recoil, small frame, good to 1k yards i assume.

 

[paul73]

A 308 AR is much bigger and heavier. I believe a 6mm ARC AR is the same size as a 5.56 but with far better ballistic performance at longer ranges.

ruger sfar is same weight as an AR15.
and price wise 6mm is totally impractical. bullets, brass, all of it. fine for the target competition bolt gun, for sure, but for a real semi-auto, no way.

 

[M1911]

ruger sfar is same weight as an AR15.

But a lot more recoil than 6mm and I’ve heard the SFAR reliability hasn’t been great.

I have an AR-10. It is a boat anchor compared to an AR-15.

I believe you can just get a 6mm ARC upper and some mags, throw it on an AR15 lower and you are off to the races. You can’t do that with 308.

 

[paul73]

SFAR reliability hasn’t been great

where/who says that?

 

[M1911]

where/who says that?

Some YouTube video that I watched. I have no direct experience.

 

[M1911]

SFAR issues

www.rugerforum.net

 

[paul73]

Some YouTube video that I watched. I have no direct experience.

well, i do own one, and trust my experience more than any 9min monetized youtube BS.

 

[mav]

This is fine as an experiment, but doesn’t pass the sniff test in a SHTF environment.

Spare parts for bolts, spare barrels, magazines, brass and ammo. I’m not disputing the stats and performance, just not particularly interested in a platform I can’t easily source.

 

[M1911]

SFAR is Junk

I would not buy a SFAR unless or until Ruger works out the issues. I have a new 20" .308 SFAR. It's light and feels put together well. However, it doesn't shoot worth a damn. I have a 1,100.00 paper weight. I have put 500 hundred or so rounds through it. The only thing that cycles reliably...

www.rugerforum.com

 

[paul73]

SFAR issues

www.rugerforum.net

whole thread screams of morons who do not know what an adjustable gas block is. it ejects all just fine. i tuned it to my reloads.

plus a gun owner who buys a gun and does not do a complete disassembly and does not check an every component before going to a range deserves all the issues they get. they write of gas blocks to be loose? so check it first, morons. it is your weapon, not rugers.

 

[LakeTrout]

i do see 6 arc as a very interesting toy, but i am totally lost of WHY i would need one, at all.
and its brass, the whole idea of the .223 AR is to shoot it at will and never bend over to pick up damn cases

That may be the whole idea for you, but a hell of a lot of people do reload .223/5.56 and pick up their brass or use a simple brass catcher. Those folks who do the type of shooting that they’re loading for probably find the advantages of the 6mm cartridge interesting.

 

[LakeTrout]

whole thread screams of morons who do not know what an adjustable gas block is. it ejects all just fine. i tuned it to my reloads.

plus a gun owner who buys a gun and does not do a complete disassembly and does not check an every component before going to a range deserves all the issues they get. they write of gas blocks to be loose? so check it first, morons. it is your weapon, not rugers.

What?? I’ve never done a complete disassembly and checked every component before going to the range. I’d also bet you that almost no one does. It sounds like you do, which is baffling to me. But the vast majority of gun owners have no idea what they’re looking at anyway, even if they did do a complete disassembly and look at everything.

Do you disassemble your newly purchased cars too and check every component too before driving it off the lot?

 

[PappyM3]

ruger sfar is same weight as an AR15.
and price wise 6mm is totally impractical. bullets, brass, all of it. fine for the target competition bolt gun, for sure, but for a real semi-auto, no way.

It’s not just the weight of the rifle. It’s also the weight of the cartridges.

Then you have reduced recoil for follow up shots.

6 Arc was quite literally developed as a better option than 308 for organic precision roles in a combat environment.

Also, I’m glad you like your SFAR, but you’re downplaying the overall experience of the product among many owners.

That may be the whole idea for you, but a hell of a lot of people do reload .223/5.56 and pick up their brass or use a simple brass catcher. Those folks who do the type of shooting that they’re loading for probably find the advantages of the 6mm cartridge interesting.

I’ve never loaded used brass before, but ha, yeah, damn straight I also pick up all my 5.56 brass. That stuff is valuable, even if it’s cheaper than 6 arc brass.

What?? I’ve never done a complete disassembly and checked every component before going to the range. I’d also bet you that almost no one does. It sounds like you do, which is baffling to me. But the vast majority of gun owners have no idea what they’re looking at anyway, even if they did do a complete disassembly and look at everything.

Do you disassemble your newly purchased cars too and check every component too before driving it off the lot?

Seriously. I do generally disassemble my firearms before using to make sure I know how they work, but I don’t buy guns expecting to have to disassemble them immediately to have to fix anything. That’s some serious PSA level quality there.

 

[paul73]

I’ve never done a complete disassembly

all stock complete uppers should be checked, if you value your safety. more than once i saw how they were done, well, sloppy.
if you don`t - you don`t, your choice.

i make my own brass catchers, so at the range i for sure pick it up. i just do not see ar15 as a range only gun. and if in the forest or on a go, i would not be picking up any brass if i am chasing any game.

 

[paul73]

downplaying the overall experience of the product among many owners.

may be.

i just know what an adjustable gas block is, and also know that ar10 is NOT an ar15 and many times it makes some effort for it to cycle properly on the loads of 150gr and then 185gr.

i use only 168 and 175 bullets, and all my guns are tuned for that ammo, and all works. when i was playing with sfar - sure you can make it not cycling at all, very easy, that is why it has an adjustable gas block.

 

[M1911]

whole thread screams of morons who do not know what an adjustable gas block is. it ejects all just fine. i tuned it to my reloads.

plus a gun owner who buys a gun and does not do a complete disassembly and does not check an every component before going to a range deserves all the issues they get. they write of gas blocks to be loose? so check it first, morons. it is your weapon, not rugers.

I’ve got three ARs. You want to know how many of them I’ve checked to see if the gas block was loose before taking it to the range? 0.

There is no excuse for shipping an AR with a loose gas block. Proper quality control should have caught that before shipping.