Hornady 6mm ARC "New" cartridge

[David Milisock]

Those interested may want to look at this.

 

[CaptnC]

The 7.62x39 and 6.5G have comparable muzzle energies and the 6.5 has higher sectional density. So if there is an instance where 7.62 is outperforming, it's due to poor choice of 6.5G ammo. Indeed, hunting to 400y with a very light-for-caliber MATCH bullet seems like a poor choice and suggests you are blaming the cartridge for your poor choice of load.

CarpeSus on youtube hunts pigs with a 90TNT very successfully with his 6.5G. And I'd suggest that ANY AR-designed caliber is near or beyond its limits at 400y for reliable hunting of hogs.

If you need 400y performance, choose a better tool for the job.

I built my 24" Grendel just to shoot steel not hunt with. I have other Grendel AR's to hunt with.

Depending on the bullet 6mm vs 6.5mm will have a better BC of roughly .100 G1 with bullets of the same weight (105 up to 108 grains). Some of the Berger bullets get even better BC.

IMO the Grendel class cases were designed to shoot bullet from 90gr up to 120gr with 100 to 110grs being the best.

Because the 6mm ARC, heavy for caliber falls into that bullet grain weight slot...on paper (pun intended) seems to be a bit better choice to shoot steel out to 600 yards.

As for a better tool...I have 6.5-06 that's is a chip shot to hit 3" steel at 600 yards (range only goes to 600). Its a blast to shoot but for each shot I can load two Grendel class cases with that same powder charge.

 

[CaptnC]

Those interested may want to look at this.

Thanks David,

I just watched your video for the first time. I wish I had watched it sooner, I could ha just referenced it to prove what I've been saying.

The data in your video is exactly why I'm going convert my 24" Grendel to a 24" ARC.

My Grendel was intended to be a range rifle so barrel length and weight are not factors for hunting use. But I want to every FPS I can so it will maximize the benefit of the higher BC.

I am a bit embarrassed to admit I do own a 10.5 6.5 Grendel, but it is suppressed and wears a ATN 4K Day/Night scope. It is only a 150 yard hunting rifle for my wife. So far I've only shot it with a pistol brace (SBR stamp should here in a couple weeks) but the accuracy has been decent with a fairly weak MV velocity of 2200fps with 120gr Barnes bullets.

The sacrifices we make to try to make something lighter. My wife is a little women so I tried to reduce the weight as much as possible...but it still weighs a ton!

Cool video! Thanks!

 

[David Milisock]

Thanks David,

I just watched your video for the first time. I wish I had watched it sooner, I could ha just referenced it to prove what I've been saying.

The data in your video is exactly why I'm going convert my 24" Grendel to a 24" ARC.

My Grendel was intended to be a range rifle so barrel length and weight are not factors for hunting use. But I want to every FPS I can so it will maximize the benefit of the higher BC.

I am a bit embarrassed to admit I do own a 10.5 6.5 Grendel, but it is suppressed and wears a ATN 4K Day/Night scope. It is only a 150 yard hunting rifle for my wife. So far I've only shot it with a pistol brace (SBR stamp should here in a couple weeks) but the accuracy has been decent with a fairly weak MV velocity of 2200fps with 120gr Barnes bullets.

The sacrifices we make to try to make something lighter. My wife is a little women so I tried to reduce the weight as much as possible...but it still weighs a ton!

Cool video! Thanks!

I did custom 30.06 loads for my sister-in-law, a little 85 lb woman required a bit of TLX to make deer hunting more enjoyable. Sacrafice for THEVGREATER GOOD!

 

[RustyPin]

In my view the 6MM ARC concept is 45 years late. Years ago a 2 man team was a spotter and shooter now with the possibilities presented by the 6MM ARC, if it pans out, a 2 man team can be a 2 man fire team.

45 years ago we had the 6mm SAW, it is a far Superior Military Cartridge. They would have changed the AR15 Platform and Magazine for the Longer OAL. Instead Congress canceled the program. IMO the Military needs to bring it back. I understand you're working under the restraints of a Platform that was designed for the 5.56, but you are. I bet it's going to be a fun little Civilian play toy as demonstrated in the Video. I follow that channel as it seems to have a very large budget.

Like I posted earlier, the Technology is already here in the form of the "Shell Shock Technologies" Case only lengthened to 350 Legend size in 6mm. The Existing AR Bolt is Easily opened up to .394 without any loss in Reliability or Strength. (This is Reality, I'm not making this up) The 350 Legend in brass holds 36.5 grains H2O and with the Superior two piece Case the capacity will increase and don't forget we're talking 90K PSI capability and Half the weight of Brass! The Magic 38 Grain threshold realistically can be achieved for Real 1000 Yard Performance. Johnny did a torture test in 2017 here:

 

[Capt. Oblivious]

For those who've indicated they don't trust the velocity numbers or performance, here's a video someone recently made, with a 16" barrel:

(Set to start when talking about 6mm ARC/throws up the velocity chart/drop table). Later, he proceeds to shoot using those calculated drop numbers, demonstrating they are actually correct.

Im not a AR “guy” but ill have that

 

[ormandj]

Anybody here tried AR-Comp yet? I'm surprised it wasn't in the load data. It's what Alliant suggested as a potential fit re: temp-stable powders, even though they hadn't done their own testing yet.

 

[David Milisock]

Im not a AR “guy” but ill have that

I have an AR 15 A2 but this cartridge has the potential to make a damn fine AR.

 

[Lkwebb]

My 24 inch x caliber 1.7 twist 5 r , 6mm arc barrel for my bolt action will be here in the next week. I'm looking forward to start my journey down this rabbit hole

 

[Laurie]

Do tell all please when you get it and get some experience in @Lkwebb

 

[Lkwebb]

Do tell all please when you get it and get some experience in @Lkwebb

I sure will, I got to see the barrel in a live chat the other day. I know he is going to test fire if before he sends it out... eagle eye shooting on YouTube is the guy doin my work..

 

[RickB]

Doc Palmisano participated in the development of the 6.5 Grendel along with Arne Brennan and Bill Alexander. Arne had been shooting a 6 PPC in an AR in NMC competition. Alexander wanted to develop a round specific to the AR platform for possible sale to DoD. Long story made short, he kept it proprietary and too expensive until the window of opportunity was all but closed before opening it up. The Grendel has since developed a following in the civilian AR community though.
According to Hornady, an undisclosed DoD entity requested that they develop

45 years ago we had the 6mm SAW, it is a far Superior Military Cartridge. They would have changed the AR15 Platform and Magazine for the Longer OAL. Instead Congress canceled the program. IMO the Military needs to bring it back. I understand you're working under the restraints of a Platform that was designed for the 5.56, but you are. I bet it's going to be a fun little Civilian play toy as demonstrated in the Video. I follow that channel as it seems to have a very large budget.

Like I posted earlier, the Technology is already here in the form of the "Shell Shock Technologies" Case only lengthened to 350 Legend size in 6mm. The Existing AR Bolt is Easily opened up to .394 without any loss in Reliability or Strength. (This is Reality, I'm not making this up) The 350 Legend in brass holds 36.5 grains H2O and with the Superior two piece Case the capacity will increase and don't forget we're talking 90K PSI capability and Half the weight of Brass! The Magic 38 Grain threshold realistically can be achieved for Real 1000 Yard Performance. Johnny did a torture test in 2017 here:

Steelheads are indeed an option. The Army has experimented with some cases which have a polymer body and brass or steel case head.
The problem with the AR platform is bolt thrust limitation. That is the reason Hornady restricted the maximum average working pressure of th 6mm ARC to 52,000 PSI. 6mm PPCs fired in bolt guns frequently exceed 62,000 PSI. There also is no standard for a 6mm PPC. Almost everyone has a different reamer.

At one time the 6x45 (6x.223) was given serious consideration, but it lacked the ability to drive the heavy for caliber bullets that the 6mm ARC is designed to shoot.
I agree that a longer magazine length receiver would have opened up options, but the service is looking for economical ways to resolve a current battlefield problem quickly. Changing barrels and magazines is about as economical as it gets. Barrels wear out somewhat quickly for frontline combat troops...they are expendable...and the 6mm ARC does not require extensive retraining of armorers or troops using it.

Federal’s .224 Valkyrie fizzled because of what, to me at least, appeared to be entirely inadequate development. The examples initially released for evaluation frankly did not shoot very well. The .224 bullets would also have been more difficult to spot for in a combat environment and the barrel life probably would not have been as good as the 6mm.

Everyone is guessing SOCOM is the undisclosed DoD client, which makes sense. They have their own procurement channels and funding. They are also dealing with smaller quantities of weapons and pretty much have Carte Blanche on choice of weapons. If SOCOM’s field experience with the 6mm ARC is satisfactory, perhaps we will see broader adoption of the round in the armed forces. Logistics are always an issue when changing weapons and ordnance. It can be worked out though.

 

[gunsandgunsmithing]

Doc Palmisano participated in the development of the 6.5 Grendel along with Arne Brennan and Bill Alexander. Arne had been shooting a 6 PPC in an AR in NMC competition. Alexander wanted to develop a round specific to the AR platform for possible sale to DoD. Long story made short, he kept it proprietary and too expensive until the window of opportunity was all but closed before opening it up. The Grendel has since developed a following in the civilian AR community though.
According to Hornady, an undisclosed DoD entity requested that they develop


Steelheads are indeed an option. The Army has experimented with some cases which have a polymer body and brass or steel case head.
The problem with the AR platform is bolt thrust limitation. That is the reason Hornady restricted the maximum average working pressure of th 6mm ARC to 52,000 PSI. 6mm PPCs fired in bolt guns frequently exceed 62,000 PSI. There also is no standard for a 6mm PPC. Almost everyone has a different reamer.

At one time the 6x45 (6x.223) was given serious consideration, but it lacked the ability to drive the heavy for caliber bullets that the 6mm ARC is designed to shoot.
I agree that a longer magazine length receiver would have opened up options, but the service is looking for economical ways to resolve a current battlefield problem quickly. Changing barrels and magazines is about as economical as it gets. Barrels wear out somewhat quickly for frontline combat troops...they are expendable...and the 6mm ARC does not require extensive retraining of armorers or troops using it.

Federal’s .224 Valkyrie fizzled because of what, to me at least, appeared to be entirely inadequate development. The examples initially released for evaluation frankly did not shoot very well. The .224 bullets would also have been more difficult to spot for in a combat environment and the barrel life probably would not have been as good as the 6mm.

Everyone is guessing SOCOM is the undisclosed DoD client, which makes sense. They have their own procurement channels and funding. They are also dealing with smaller quantities of weapons and pretty much have Carte Blanche on choice of weapons. If SOCOM’s field experience with the 6mm ARC is satisfactory, perhaps we will see broader adoption of the round in the armed forces. Logistics are always an issue when changing weapons and ordnance. It can be worked out though.

I spoke with Bill Alexander in 2006-7 when I was just beginning to test necking the Grendel up to 30 cal. His words to me at the time were that I could do anything I wanted to do with their cartridge, as long as I didn't call it a Grendel, because the name is what was protected, rather than the case. Hence the name 30 Major instead of 30 Grendel.

 

[Rustytigwire]

Ordered my 6arc barrel last week. Hope it gets here before the (election) Halloween/ Thanksgiving.
I bought a 24 inch 9 tw to shoot 87 vmax and 70 blitz king at helpless rodents. AR15 service.
Neck down 6.5 brass, trim, trim neck thickness.
Im not sure about sizing and seating dies availability. Going to keep an eye out but attempt purchase (availability?) mid September.
I bought a 6.5 and am developing loads. The muzzle threads were not straight enough for my suppressor so surgery scheduled for this week. Magazines and brass soon in service. Hoping to sort bugs till the 6 gets here.
So much fun to be had, so little time.

 

[Lkwebb]

Here is my gunsmith shooting his 6mm arc.
I'm still waiting on my barrel to get here.

 

[Lkwebb]

 

[RustyPin]

Doc Palmisano participated in the development of the 6.5 Grendel along with Arne Brennan and Bill Alexander. Arne had been shooting a 6 PPC in an AR in NMC competition. Alexander wanted to develop a round specific to the AR platform for possible sale to DoD. Long story made short, he kept it proprietary and too expensive until the window of opportunity was all but closed before opening it up. The Grendel has since developed a following in the civilian AR community though.
According to Hornady, an undisclosed DoD entity requested that they develop


Steelheads are indeed an option. The Army has experimented with some cases which have a polymer body and brass or steel case head.
The problem with the AR platform is bolt thrust limitation. That is the reason Hornady restricted the maximum average working pressure of th 6mm ARC to 52,000 PSI. 6mm PPCs fired in bolt guns frequently exceed 62,000 PSI. There also is no standard for a 6mm PPC. Almost everyone has a different reamer.

At one time the 6x45 (6x.223) was given serious consideration, but it lacked the ability to drive the heavy for caliber bullets that the 6mm ARC is designed to shoot.
I agree that a longer magazine length receiver would have opened up options, but the service is looking for economical ways to resolve a current battlefield problem quickly. Changing barrels and magazines is about as economical as it gets. Barrels wear out somewhat quickly for frontline combat troops...they are expendable...and the 6mm ARC does not require extensive retraining of armorers or troops using it.

Federal’s .224 Valkyrie fizzled because of what, to me at least, appeared to be entirely inadequate development. The examples initially released for evaluation frankly did not shoot very well. The .224 bullets would also have been more difficult to spot for in a combat environment and the barrel life probably would not have been as good as the 6mm.

Everyone is guessing SOCOM is the undisclosed DoD client, which makes sense. They have their own procurement channels and funding. They are also dealing with smaller quantities of weapons and pretty much have Carte Blanche on choice of weapons. If SOCOM’s field experience with the 6mm ARC is satisfactory, perhaps we will see broader adoption of the round in the armed forces. Logistics are always an issue when changing weapons and ordnance. It can be worked out though.

I've got a ton of respect for SOCOM. You never know when they are on the Horn. Any application they see fit will be different than a generic IMO.

 

[Hohn]

It’s not just the JSOC had the flexibility to procure things on an expedited basis; it’s that Big Army acquisitions are so political and broken that it’s a miracle when they get anything done.

Id really like to see the 6ARC in a bolt gun that takes AR mags. The additional performance at higher pressures should get you a legitimate 2800 or so with a 108 in a 20” barrel. And in a super light < 6# gun you have mild recoil and remarkable capability.

Something like a Ruger American Predator in 6 ARC with up to 20+ rounds in a mag? Sounds like the perfect walking/offhand rifle to me. Give it a lightweight 4x or 6x AR scope and it would be awesome.

 

[ormandj]

Anybody with Quickload who's mocked up a 6ARC case able to run some numbers with a 108 ELD-M and AR-Comp? I'm looking for loads to keep it at or below 52kpsi, but there's no published data yet, and pressure signs won't show up until much higher pressures. I realize QL is just an estimate, but it's better than what I have now.

 

[Hohn]

In the case size, AR comp should be about the perfect powder. H4895 also.