New 6mm Advanced Rifle Cartridge

yellowfin

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what is the brass life of this 6mmARC compared to 224V from an AR?
Good question, and while I don't have an answer for that directly I could say that I would expect barrel life to be better so if there's a deficit on brass life the cost could be offset by the barrel longevity.
 

RTV

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Curious as to why Magpul never made 6.5 Grendel mags.
Because the walls of the mag have to be too thin with a grendel to fit inside an ar15 magwell for it to be reliable.

That is why magpul teamed up with LWRC for the Six8 in the 6.8spc. Same issue.
 

RTV

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I think I am going to try converting am LWRC Six8 to 6mm ARC. If the magpul mags are reliable this could very easily be my go to rifle.

Anyone have experience using grendel in a Six8?
 
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Nimothy

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Not outside the realm of possibility, but on the top end for sure. In the "by the inch" test I saw 18" was around 2600fps. I have a Cz527 that is in 6 ARC with an 18" barrel that is also right around 2600fps with 108's.

Some barrels are faster than others. Like I said, 100fps isn't outright bogus but I wouldn't expect it to happen every time.

ETA: My rifle is a custom build, not saying CZ will be making factory 6 ARC's. They should, but I don't know if they will or not.
Do you handload it? If so, What’s the case capacity? Is this a “varget” cartridge?
 

Ledzep

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Do you handload it? If so, What’s the case capacity? Is this a “varget” cartridge?
I've only had the rifle together for a couple weeks now and have been shooting a small supply of factory ammo. I believe Varget is one of the go-to's. Varget is slow.
 
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Ndbowhunter

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I haven’t been chasing the intermediate unicorn cartridge too hard. The 223 with either 77gr tmk in stanag confines or its AI brother and aics mags With heavies is plenty for my needs.

or 32gr varget at 105’s or 28gr 4198 does the same for common fast twist 243 bolts.

but the allure of factory fodder and a .53 at 2700 at 52k psi.. sign me up.
 

ajwcotton

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I was under the impression that Hornady was saying 2850 from an ar the one in the video was shorter than 22
They say 2750 from a 24 for the 108's so getting 2700 from a 22 is reasonable.
There are a couple in the video it's the one with the stainless barrel and little bastard brake.
 
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RTV

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It’s an easy fix with a file to make Grendel work 100% in Magpul Six8 mags, even the 30 rounders.
Kinda defeats the purpose though at that point...

I was trying to find some mags that would be trust your life dependable however if you have to make modifications to them to get them to work I would never trust my life to it.
 
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cw11

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Is it possible this new 6mm arc ammo becomes widely mass produced to bring costs of ammo down similar to 5.56/.223? Surely won’t be quickly but maybe over the course of several years if it becomes widely adopted by the military. I’ve been hoping at some point there could be a cartridge in between 5.56 and 308, other than 7.62x39, that could be had for .25-.35 per round. FMJs of course.
 

MPrimo

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Does anyone have any experience with the Ballistic Advantage barrels offered by Brownells? This looks like the best configuration for accuracy & distance as Proof is only making up to an 18" barrel. 24" might be overkill but 22" looks like what I'm after but I don't know much about the manufacturer. Or should I just go 18" Proof?

 
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Lunchbox27

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I'm interested in this, but I'll wait for offerings from Craddock Precision or Keystone Accuracy for the build.
 
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Kamerad

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Is it possible this new 6mm arc ammo becomes widely mass produced to bring costs of ammo down similar to 5.56/.223? Surely won’t be quickly but maybe over the course of several years if it becomes widely adopted by the military. I’ve been hoping at some point there could be a cartridge in between 5.56 and 308, other than 7.62x39, that could be had for .25-.35 per round. FMJs of course.
You’ve just described 6.5 Grendel, regarding FMJ price per round.
 
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mark5pt56

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I wonder if LMT will make barrels in this caliber for the MRP? I certainly hope they don't follow the "testing" they supposedly do and have to fire 200,000 to make sure they work. ( heard they did this long ago with 6.8.
 
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ChadL

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I had a 6 x 6.8 in an AR and it was soo much fun. I shot many varmints and a white tail with it too. I forget what my varmint load was but it was a blitzking in the 70 grain weight area. IIRC I was pushing those over 3,200 fps.....ground hogs hated those rounds....I mean HATED :). Anyway, I did away with that setup some time ago and have regretted it from time to time. It was really fun. The 6mm ARC definitely has my interest. 6mm is a really versatile bullet.
 

Nimothy

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Does anyone have any experience with the Ballistic Advantage barrels offered by Brownells? This looks like the best configuration for accuracy & distance as Proof is only making up to an 18" barrel. 24" might be overkill but 22" looks like what I'm after but I don't know much about the manufacturer. Or should I just go 18" Proof?

i have a 308 .936 barrel from them that is surprisingly accurate. (I had to send one back, they took care of me payed shipping both ways) and two 556 barrels. They are super nice dude. Best for the money if you ask me. I’m pretty sure they make barrels for lots of manufacturers (aero, brownells retro line, etc) I will day if what you want is in stock buy it. They don’t have manufacturing to keep up with demand, EVERYTHING I ever want from them is ALWAYS out of stock. So if they have the barrel you want chances are it won’t be in stock for over a year if it sells out. (What’s worse they will send you a sale flyer saying it’s on sale and not have any. Hahahaha)
 

Ledzep

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Do you handload it? If so, What’s the case capacity? Is this a “varget” cartridge?
Earlier post was wrong. Varget is okay, but runs slower MV than a few others. XBR8208 and 4895 work well all around (75-110), and Benchmark and CFE223 work for lighter stuff (75-90gr). Don't have any info on lighter varmint bullets yet.
 
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Nimothy

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Earlier post was wrong. Varget is okay, but runs slower MV than a few others. XBR8208 and 4895 work well all around (75-110), and Benchmark and CFE223 work for lighter stuff (75-90gr). Don't have any info on lighter varmint bullets yet.
So it’s like a 6br, did you find the capacity?
 

Gtscotty

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The PRI 6.8 Mags also work for Grendel. Been done for a long time.
The PRI 6.8 waffle mags? I tried my one remaining PRI waffle mag with my Grendel when I first got it, and the mag wouldn't feed more than about 4 rounds worth a damn. Same rifle slurps Grendel rounds out of newer ASC mags smoothly and reliably. The PRI mag worked great with my 6.8, I just didn't have any luck running Grendels from it.
 
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vmpglenn

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Kinda defeats the purpose though at that point...

I was trying to find some mags that would be trust your life dependable however if you have to make modifications to them to get them to work I would never trust my life to it.
It's just removing a couple of internal ribs to allow correct round stacking, but yeah, if you need out of the box compatibility the Six8 mags ain't it.
 

mavrick10_2000

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Does anyone have any experience with the Ballistic Advantage barrels offered by Brownells? This looks like the best configuration for accuracy & distance as Proof is only making up to an 18" barrel. 24" might be overkill but 22" looks like what I'm after but I don't know much about the manufacturer. Or should I just go 18" Proof?

Very decent barrels for hunting and decent/good groups in relation to those sort of activities. I've read plenty of reports in 5.56 being sub moa from people who can be a bit picky.

However, If you're wanting precision steel/paper punchers, PRS type stuff for long range I'd wait for Craddock, Bartlein and the usual suspects for those specific needs just for the extra insurance.
 
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mark5pt56

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KaM

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Does anyone have any experience with the Ballistic Advantage barrels offered by Brownells? This looks like the best configuration for accuracy & distance as Proof is only making up to an 18" barrel. 24" might be overkill but 22" looks like what I'm after but I don't know much about the manufacturer. Or should I just go 18" Proof?

It looks like ARP is going to have a 20" barrel soon.

Edit- Not til fall.
 
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slockwood

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I'm copy and pasting from my FB post yesterday wish I seen this sooner.

Hornady has announced it's new cartridge the 6mm ARC. A lot of questions are going to be raised from this and a lot of misinformation will also be passed.
This cartridge was designed to be an "intermediate" (long range) round to be effective to 800 yards. Virtually eliminating the 308/7.62 platform.
Can this round compete with a 308 at that distance. Simple answer is yes. This is not a cartridge designed to make you get rid of an ar10 but to offer that same capability to those that only have a small frame. As well as working within budget and supply restraints of the mil/le agencies out there.

When I was first made aware of this a little over a year ago, i said if we can get BR velocity out of an AR it will be a winner. Also there just seems to be something about the inherent accuracy of these short stubby cartridges.

Why shorten a grendel case, because it allows the optimum neck/shoulder/bullet heel marriage which is easily lost on the heavies loaded to ar mag length. Factory 108s are 2.260 and feed flawlessly in elander grendel 10-20 round mags.

Bolt face is grendel 2

Factory ammo offering, yes. Most large distributors have or will have ammo in the next day or two from Hornady. Who else is offering ammo is TBD

Die options. Hornady has them. In the beginning I used a grendel body die, bumped shoulders with a 6ppc die and trim/chamfered/deburred with a giraud and a 6mm AR case holder.

Complete firearms. Lantac-USA of course 😉

Can you form from grendel brass, yes. This opens options such as federal, norma, lapua, starline etc.

So far load developments have happened with H4895, IMR4166 and N140 all with 108eld.

In upcoming weeks I'll be putting out more info and running any test feasibly possible.

Please ask away, and I will answer anything I can.
 

Attachments

slockwood

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6 ARC


COAL to lands


Hornady 108 eld - 2.311
Hornady 105 bthp - 2.230
Sierra 107 - 2.147
Sierra 110 - 2.442
Berger 105 hybrid - 2.368
Berger 109 hybrid - 2.361
Nosler 105 rdf - 2.304


BTO


Hornady 108 eld - 1.758
Hornady 105 bthp - 1.748
Sierra 107 - 1.602
Sierra 110 - 1.759
Berger 105 hybrid - 1.760
Berger 109 hybrid - 1.761
Nosler 105 rdf - 1.738

Resized_20200603_195213%281%29.jpg
 

mark5pt56

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So, two of those will fit into a 6.5G mag?



6 ARC


COAL to lands


Hornady 108 eld - 2.311
Hornady 105 bthp - 2.230
Sierra 107 - 2.147
Sierra 110 - 2.442
Berger 105 hybrid - 2.368
Berger 109 hybrid - 2.361
Nosler 105 rdf - 2.304


BTO


Hornady 108 eld - 1.758
Hornady 105 bthp - 1.748
Sierra 107 - 1.602
Sierra 110 - 1.759
Berger 105 hybrid - 1.760
Berger 109 hybrid - 1.761
Nosler 105 rdf - 1.738

View attachment 7343311
 

Gtscotty

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I'm copy and pasting from my FB post yesterday wish I seen this sooner.

Hornady has announced it's new cartridge the 6mm ARC. A lot of questions are going to be raised from this and a lot of misinformation will also be passed.
This cartridge was designed to be an "intermediate" (long range) round to be effective to 800 yards. Virtually eliminating the 308/7.62 platform.
Can this round compete with a 308 at that distance. Simple answer is yes. This is not a cartridge designed to make you get rid of an ar10 but to offer that same capability to those that only have a small frame. As well as working within budget and supply restraints of the mil/le agencies out there.

When I was first made aware of this a little over a year ago, i said if we can get BR velocity out of an AR it will be a winner. Also there just seems to be something about the inherent accuracy of these short stubby cartridges.

Why shorten a grendel case, because it allows the optimum neck/shoulder/bullet heel marriage which is easily lost on the heavies loaded to ar mag length. Factory 108s are 2.260 and feed flawlessly in elander grendel 10-20 round mags.

Bolt face is grendel 2

Factory ammo offering, yes. Most large distributors have or will have ammo in the next day or two from Hornady. Who else is offering ammo is TBD

Die options. Hornady has them. In the beginning I used a grendel body die, bumped shoulders with a 6ppc die and trim/chamfered/deburred with a giraud and a 6mm AR case holder.

Complete firearms. Lantac-USA of course 😉

Can you form from grendel brass, yes. This opens options such as federal, norma, lapua, starline etc.

So far load developments have happened with H4895, IMR4166 and N140 all with 108eld.

In upcoming weeks I'll be putting out more info and running any test feasibly possible.

Please ask away, and I will answer anything I can.
I'm guessing 6.5 Staball is going to be too slow for this cartridge, but it seems to do well in the 6GT, know if anyone has tried it yet?
 

slockwood

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I'm guessing 6.5 Staball is going to be too slow for this cartridge, but it seems to do well in the 6GT, know if anyone has tried it yet?
I have no plans to try staball. If i do it will be lower on the list. I know someone who tried it in a grendel variant and performed but also had almost 3gr more h2o capacity