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Old December 11, 2018, 10:33 AM   #1
ed308
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Army's new 6.8 cartridge with development information:

Another article on the Army's new 6.8 cartridge with development information:

https://www.militarytimes.com/news/y...-lot-deadlier/
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Old December 11, 2018, 01:27 PM   #2
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Old December 11, 2018, 03:46 PM   #3
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Great...I just bought the 6.5 Grendel, I couldn't make up my mind and thought the military had given up on the 6.8.

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Old December 11, 2018, 04:02 PM   #4
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I think this 6.8 is caseless.

And the issue with lethality is armor piercing bullets tend to poke holes not mushroom.

They don't say they have that resolved. A slightly larger caliber bullet is not going to make any difference if its still AP (unless there is some whiz bang tech to let it do both)
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Old December 11, 2018, 04:30 PM   #5
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This is one of the proposals

https://hiconsumption.com/2018/10/fd...ss-ammo-rifle/

Its not the 6.8 caliber, I think its pie in the sky, other serious proposals out there.

A bit more on it

https://www.wearethemighty.com/gear-...lti-bore-rifle

And more on the program.

https://www.wearethemighty.com/news/...67974963249478
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Old December 11, 2018, 08:21 PM   #6
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This is not 6.8 SPC. The demonstration models shown have used a bimetal case that appears to be based on a .308 case. The case head is made out of a different metal - probably to contain the higher pressures. It uses an AR10 action.

One of the stated target goals is to penetrate any existing known body armor at 600m. So, it is going to have some energy. The rumored specs are it will be able to launch a 125gr bullet at 3,500fps out of a 16” barrel.

It is also being developed with an all-purpose, super-duper, day/night/thermal optic that displays the recticle on a heads up display according to the latest Military Times article. Some cast off from Land Warrior I’d guess.
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Old December 11, 2018, 08:30 PM   #7
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Quote:
This is not 6.8 SPC.
No, it was developed from 6.8 SPC.
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Old December 11, 2018, 09:09 PM   #8
Bartholomew Roberts
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Yup, except for the case, powder, primer, and bullet construction. But it is sure the same diameter... though the diameter is actually flexible so long as it meets the performance requirement. It was just determined 6.5-7mm offered the best chance of that.
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Old December 11, 2018, 09:38 PM   #9
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But it is sure the same diameter...
It is more than that. It is a direct development....something many experts on these boards claimed it was not.




Quote:
A 2006 Joint Service Wound Ballistics-Integrated Product Team report showed the “clear and unequivocal best performing” cartridge tested was 6.8mm.

In 2007, the Army’s 5th Special Forces Group approached ARDEC with interest in the 6.8mm Special Purpose Cartridge. ARDEC evaluation deemed the caliber “very effective” in an assault rifle platform, Kowal said.

Roberts wrote in his presentation that testing to develop the 6.8mm looked at bullets including 6mm, 6.5mm, 6.8mm, 7mm and 7.62mm.

The 6.8mm offered the best combination of “combat accuracy, reliability, and terminal performance for zero to 500-yard engagements in an M4-sized package.”

In 2015, the Small Arms Ammunition Configuration Study showed similar results, pointing to an intermediate caliber as the best option.
But the study pushed for higher muzzle energy for extending range and lethality at impact, while maintaining bearable recoil and consistent accuracy.
Only it wasn't 5th Group but that's ok....they can take the credit, LOL.

https://www.militarytimes.com/news/y...-lot-deadlier/
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Old December 11, 2018, 10:16 PM   #10
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The most interesting thing I keep hearing about with the new mystery cartridge is its chamber pressure.

https://www.businessinsider.com/army...ank-gun-2018-2
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Old December 11, 2018, 10:36 PM   #11
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“This is a weapon that could defeat any body armor, any planned body armor that we know of in the future,” Army Chief of Staff Gen. Mark Milley told Military Times.

So, this 6.8 mm cartridge is better at penetrating body armor than 30-06 AP? How does it do this? What sort of recoil can we expect from a cartridge that defeats level IV or better body armor?



I respect Dr. Roberts' thoughts on terminal ballistics and that was a good addition to the article. Roberts has been keen on the 6.8 SPC for military use and has recommended many 5.56 loads for civilian and law enforcement use that are superior to M193, M855 and M855a1 ball that the military must use.
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Old December 12, 2018, 08:03 AM   #12
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So, this 6.8 mm cartridge is better at penetrating body armor than 30-06 AP? How does it do this? What sort of recoil can we expect from a cartridge that defeats level IV or better body armor?
Not just defeats any known body armor; but defeats any known body armor at 600m using an EPR bullet. When you think about what that means in terms of energy, it is pretty clear that whatever problems such a round might have, terminal ballistics is unlikely to be one of them.

Also, if you read the Military Times linnk where they explain the magic sight that will sit on the magic rifle, it seems they are also contemplating something similar to TrackingPoint.

The thing is, if the materials and powder development that would allow these types of technological advances existed, you’d think they would have been used somewhere else already.

Last edited by Bartholomew Roberts; December 12, 2018 at 08:12 AM.
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Old December 12, 2018, 10:48 AM   #13
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Quote:
Originally Posted by Bartholomew Roberts View Post

The thing is, if the materials and powder development that would allow these types of technological advances existed, you’d think they would have been used somewhere else already.

This is called “Techonolgy Pull”, defining a requirement for new procurement that cannot be met with current production tech and paying for development to get there or closer to there. It occurs all the time, but especially in Aerospace.



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Old December 12, 2018, 11:58 AM   #14
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Quote:
It is more than that. It is a direct development....something many experts on these boards claimed it was not.
I disagree.
I see it as a totally different development.
6.8 SPC merely sparked their interest ... along with 120+ years of other work in the 6.5-7.7mm caliber range. Many militaries have focused on 6.8mm as seeming to be the 'ideal' caliber, for many decades - almost since the advent of smokeless powder.


I see this new 6.8 development, in reference to 6.8 SPC, as something even more ridiculous than .308 Winchester being a "stretched .300 Savage". You can't stretch a .300 Savage to .308 Winchester. A new case must be made.

The engine in my truck can trace its roots all the way back to a small displacement V4 (yes, four cylinder, V-configuration) that was made and used in England in the 1950s.
But if you put my Illinois-made, fuel-injected, overhead cam, composite gasket, aluminum 4.0L V6 next to that cast iron, carbureted, low compression, leather gasketed, pushrod 1.2L V4, you'll instantly recognize that the inspiration for something doesn't necessarily mean that the end result will resemble the origin in any way ... other than performing a similar basic function (such as being an engine that provides rotational force, or being a cartridge that launches bullets).
The 4.0L V6 in my truck now actually has more in common with a Duesenberg straight-8 (Model A) than it does with the V2 it supposedly evolved from.

The current military 6.8 development program has, in my opinion, nothing more to do with 6.8 SPC at this point than sharing the same nominal caliber. (And I use the word 'nominal', as it's possible that they could end up with a .275" or .280" projectile and have absolutely nothing to do with 6.8 SPC by the time anything makes it to trials [if ever].)
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Old December 12, 2018, 12:14 PM   #15
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Quote:
6.8 SPC merely sparked their interest
It was the foundation and starting point on which further development was based upon.

Before Bush's September 11th mandates and directed synergy of operators with engineers, there was little interest in upgrading the US Army small arms outside of further development of 5.56mm.

After some operators developed a wildcat round and modified some M4's it greatly peaked the interest of the DoD's as well as civilian cartridge engineers. This lead to multiple levels of co-operation amongst civilian manufacturers and direct input of operators that did not exist beforehand and instigated many improvements.

While you are correct it is not the same cartridge as 6.8mm SPC you are not correct in the significance. 6.8mm SPC is very much the foundation of this new cartridge and maybe one day the full story will come out.

That should be obvious from the plethora of articles all mentioning the roots of this new cartridge as 6.8mm SPC.

Quote:
The current military 6.8 development program has, in my opinion, nothing more to do with 6.8 SPC at this point than sharing the same nominal caliber. (And I use the word 'nominal', as it's possible that they could end up with a .275" or .280" projectile and have absolutely nothing to do with 6.8 SPC by the time anything makes it to trials [if ever].)
No more so than the Wright Flyer has to do with a Boeing 747....

Or are you saying the Boeing 747 is not a development of the Wright Flyer??
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Old December 12, 2018, 12:39 PM   #16
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This is called “Techonolgy Pull”, defining a requirement for new procurement that cannot be met with current production tech and paying for development to get there or closer to there. It occurs all the time, but especially in Aerospace.
Exactly. The focus of where the technology pulls is located has been the impediment to getting a more lethal weapon system in a soldiers hand than 5.56mm in the past. The point of this article is that is no longer a requirement. The focus has shifted.

We were very much aware of the failures of DoD's ACR program. We wanted and needed something more lethal after combat experience in the GWOT with 5.56mm.


Quote:
Rather than an overhaul, Schatz advocated for switching to the intermediate caliber on the existing platforms, with adjustments that included integrated suppressors, tailorable weapons systems, polymer casings, recoil reduction, one-way tracers and improved fire controls — all technologies in the commercial market.

But Pentagon officials and Army weapons programs wanted more than a better caliber — they wanted a “leap ahead” technology that would deliver capabilities beyond the numerous adjustments that transformed the original M16A1 into the M4 carbine.

Officials opted instead for somewhat of a clean slate, but with echoes of past programs and technologies that have been in development for decades. They also focused on integrating advanced targeting, data and training as the path to advancing small arms lethality.

The focus is not the rifle anymore but seeing the soldier as an integrated combat system. In otherwords, we are not waiting on a Plasma Rifle in the 40 watt range to dump the 5.56mm.
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Old December 12, 2018, 12:49 PM   #17
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Quick look into this...
in simple terms, it’s a squad machine gun that will use caseless ammunition with a bullet diameter of 6.8 mm. Seems to have no relationship to 6.8 spc aside from being a similar diameter.
If we wanted a traditional cased cartridge that is a more powerful 6.8mm... well that’s been in existence for 93 years already in the form of the .270win.

The similarities end at bullet diameter. Kinda like saying a Corvette was developed from Chevette because the name is similar.

Basically not going to get any real benefit without ditching the case.
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Old December 12, 2018, 01:44 PM   #18
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Eh, if this ever becomes more than a fantasy program on the bullet point of some general officer’s eval, the final caliber will be 6.5 in any case - because that’s going to end up being the most ballistically efficient and you are pushing the limits of ballistics and need every edge available. Plus since you are producing a muzzle energy of 3,400 ft/lbs, the terminal ballistics advantages of 0.3 or 0.5 extra mm of diameter at the same energy are basically irrelevant for any practical purpose.

Quote:
Originally Posted by davidsog
n otherwords, we are not waiting on a Plasma Rifle in the 40 watt range to dump the 5.56mm.
No, we’re just waiting on a 16” rifle that outperforms .270 WSM with a 26” barrel, loses less than 10% accuracy after 10,000 rounds, weighs less than the M4, and has a Trackingpoint-enabled day/night/thermal HUD sight. I’m not sure I’d want to bet on which one comes along first.

Last edited by Bartholomew Roberts; December 12, 2018 at 01:53 PM.
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Old December 12, 2018, 02:09 PM   #19
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And there you have it. Well said

Quote:
No, we’re just waiting on a 16” rifle that outperforms .270 WSM with a 26” barrel, loses less than 10% accuracy after 10,000 rounds, weighs less than the M4, and has a Trackingpoint-enabled day/night/thermal HUD sight. I’m not sure I’d want to bet on which one comes along first.
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Old December 12, 2018, 07:44 PM   #20
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My take on this:

There is not enough difference for a military caliber between 6.5 to 6.8 to make any difference for the military design intent (6 mm is now the new popular target round but that does not mean its the best military design despite the wondrous BC)

And I disagree the 6.8 sparked anything, the 5.56 thingy sparked the 6.8, the 5.56 sparked the new as well. The derive from the same cause. The original 5.56 tumbled and was useful on skinny people in jungles at short ranges (unstable) - not so much at longer ranges and less so as they shortened the M16 20 inch to the M4.

Nothing more than a bullet design that will go into whatever they settle on, fully telescopic or semi telescopic ammo.

What the military is asking for in the bullet is a multi dimensional whiz bang and they designed the new one themselves.

So what they want is good armor penetration to 600 m, accurate, hopefully actually kills people effectively. So its going to be a compromise BC (longer but not as long as ELD) with whatever features they can design in.

The last time I saw the hoopla, the goal of armor penetration (and other things) was the main driver and acualy killing people was secondary.

Will see what they come up with.
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Old December 12, 2018, 08:10 PM   #21
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No more so than the Wright Flyer has to do with a Boeing 747....

Or are you saying the Boeing 747 is not a development of the Wright Flyer??
Absolutely.
No matter how you look at it, the technology is totally different.
...And the Germans did it first, not the Wrights. (Including the first powered flight.)

The only common theme: Fluid dynamics. Or, more specifically, Aerodynamics.
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Old December 12, 2018, 09:04 PM   #22
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People can disagree.

Does not mean the facts are not:

Quote:
A 2006 Joint Service Wound Ballistics-Integrated Product Team report showed the “clear and unequivocal best performing” cartridge tested was 6.8mm.

In 2007, the Army’s 5th Special Forces Group approached ARDEC with interest in the 6.8mm Special Purpose Cartridge. ARDEC evaluation deemed the caliber “very effective” in an assault rifle platform, Kowal said.

Roberts wrote in his presentation that testing to develop the 6.8mm looked at bullets including 6mm, 6.5mm, 6.8mm, 7mm and 7.62mm.

The 6.8mm offered the best combination of “combat accuracy, reliability, and terminal performance for zero to 500-yard engagements in an M4-sized package.”

In 2015, the Small Arms Ammunition Configuration Study showed similar results, pointing to an intermediate caliber as the best option.
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Old December 12, 2018, 09:12 PM   #23
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This ain’t that bullet. Completely different concept all together.

What it does say is that they are looking at a 6.8mm bullet for the pretty much nonexistent weapon.

Highlighting special forces means nothing really.
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Old December 12, 2018, 09:16 PM   #24
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This ain’t that bullet. Completely different concept all together.
It is not the 6.8mm SPC but it is developed from it as the article says.......
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Old December 12, 2018, 09:20 PM   #25
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I’ll agree, that it says the 6.8spc kinda worked but they are going to have to completely reinvent the military weapon to make it worthwhile.
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