Army selects 6.8mm as the new common round...

[Sharkbite]

My understanding :The 300 Blackout was developed by J D Jones as a cartridge to fling heavy,high ballistic coefficient 30 cal bullets at subsonic muzzle velocities.

Almost, the 300 WHISPER was a JD Jones wildcat round. Based around subsonic loadings out of single shot pistols like the T/C Contender

Advanced armament corp (AAC) got the 300 blackout SAMMI approved and standardized. They wanted a round that would work in an AR platform with minimal mods to the gun and run both subsonic AND supersonic loads.

We now have both subs that suppress well out of an AR and supers that give AK ballistics. All with just a mag/ammo swap. No adjustment to the gun needed to switch roles.

Im not saying 300blk should be the next Mil round. I think the 6.8 idea holds promise for a mil round, given the limitations placed on mil ammo design.

[stagpanther]

You do realize there are some 45 different kinds of 7.62MM Nato in the inventory???

I do now.

I'm having a bit of trouble understanding what position you're fighting for--unless you're just fighting for the heck of it?

[globemaster3]

So what we know based on all the links and data:

The new 6.8 GP is NOT the 6.8 SPC and ONLY shares bullet diameter in commonality. Darn, I was hoping for an upcoming supply of cheap plinking ammo for my 6.8 ARs....

There are drawings out there of the new cartridge. But none of them have been shared with anyone outside of the project for us to get an idea of case shape/capacity, etc.

These companies are building prototypes:
AAI Corporation Textron Systems.
• FN America LLC.
• General Dynamics-OTS Inc.
• PCP Tactical, LLC.
• Sig Sauer, Inc.
Some good names in there.

And finally, this is a 27-month period for development.
Meh, I would have preferred 69 weeks, but oh well. (insider joke)

[globemaster3]

@ davidsog

So you are going to change rounds in the middle of the fight? Or run to the closet to select a different ammo type??

Off topic:

2001-2005, while flying C-17s and airdropping bubbas like you purport to be, that's EXACTLY what senior AF leaders expected of us when they issued a mag of ball and a mag of HP for our 9mm... We were supposed to fly with HP to limit damage to the aircraft if we needed it for anti-hijacking, but once we got shot down or landed somewhere, we were supposed to switch to ball.

Seriously, that's what the JAG briefed us and we had to sign an understanding of that which probably went into a circular file somewhere...

Should have seen our faces on that declaration... And we all knew which guidance would be thrown out the minute the situation dictated.

[stagpanther]

The new 6.8 GP is NOT the 6.8 SPC and ONLY shares bullet diameter in commonality. Darn, I was hoping for an upcoming supply of cheap plinking ammo for my 6.8 ARs

I don't think anyone was saying that the new cartridge would BE the 6.8 spec--though I would argue it's not a bad place to start.

Maybe we should start an on-line lottery and have people submit their guesses as to what the final cartridge configuration will be.

[RC20]

That is because its going to be caseless telescopic or fully combusting case.

Also why its going to take so long and the costs are so high for so many companies.

They want the best possible choices (or so they say).

[davidsog]

2001-2005, while flying C-17s and airdropping bubbas like you purport to be, that's EXACTLY what senior AF leaders expected of us when they issued a mag of ball and a mag of HP for our 9mm... We were supposed to fly with HP to limit damage to the aircraft if we needed it for anti-hijacking, but once we got shot down or landed somewhere, we were supposed to switch to ball.

Glad you replied. The perception from some in this thread is the military is limited in their ammo selection.

Never was an issue with JAG. Heck, I used to keep 90mm Recoiless Rifle Flechettes in my nametape on the back of my PC as a private. It was like a right of passage when you did a live fire with them supporting you. If you have ever seen what that does to people, it is hard to whine about a small piece of lead.

I think the Army just handles it as the ammo is not modified from the factory and killing the enemy efficiently is not creating "cruel and unusual suffering". The US has been up before the Hague several times on this issue.

[davidsog]

The new 6.8 GP is NOT the 6.8 SPC and ONLY shares bullet diameter in commonality.

Maybe I misread it but I understand it is a development of the 6.8 SPC. It is been refined by the engineers or mucked up by big Army.

[globemaster3]

When I was at the squadron and had all the links pulled up as well as the Early Bird article, one of them clearly stated it was not the 6.8 SPC...

So, you might have it both ways! It could be “refined” by the engineers AND the Army could have mucked it up!

[davidsog]

It is not surprising they have made changes. The original 6.8mm SPC was a wildcat and literally made by a couple of operators in their garage.

A Remington engineer took interest, further refining it which started the ball rolling.

[marine6680]

I wouldn't change loads mid fight...

No, I have loads that are suitable for the various tasks they may need to perform. I load up with the ammo appreciate for what I am doing. I will use different ammo when outdoors in predator territory, than what I use for HD... Or other such things.

I have that luxury... The likelihood of needing to switch loads quickly is near zero.


And it's not that the military doesn't have a large selection of ammo types... It's that they suck... They are limited to certain design criteria. The whole phenomenon of pushing the limits of acceptable ammo type is a bit more modern, being a quest to improve upon the poor performance of 855, spurred by the long ongoing insurgency we are fighting.

There are several types of each caliber in use... 5.56 has something like 25 different loads on the books.

You have things like...

Ball
Tracer
Grenade
Frangible
Armor piercing
Dim tracer
Dummy
Practice
Etc...

And you may have a couple of each type, of slightly different specs.


It's not about the military not have a wide ammo selection to choose from... It's that the choices they have available for combat are not very effective... Recent developments have lead to better ammo for the field. They are just not highly common quite yet. It take a few years for a new ammo type to get fully implemented. Usually it goes to the places that need it most first.

[Jim Watson]

Yup.
Providing AP and especially tracer can add to the problems of a new round.
We owe the present 5.56 7 twist to the long long tracer bullet.

[davidsog]

The whole phenomenon of pushing the limits of acceptable ammo type is a bit more modern, being a quest to improve upon the poor performance of 855, spurred by the long ongoing insurgency we are fighting.

It is not overcoming the limitations of a single round design. It is overcoming the physics of a SBR at CQB ranges AND having something that is going to be effective at intermediate combat ranges.

5.56mm just does not cut the mustard and is a mediocre performer at intermediate ranges and poor at CQB ranges. There is no wonder bullet that breaks that barrier or alters the physical limitations.

The significance of the engineering studies is that a SBR at CQB ranges the physics dictates the round caliber is almost inconsequential. Therefore get something that performs much better at intermediate ranges and take the slight improvement at CQB ranges a larger caliber round offers.

[ed308]

I keep reading rumors its the .277 Wolverine (6.8x39). It uses the same mags and brass as .223/5.56 but the performance is lacking IMO. Back in 2014, they were testing Murray's 7mmUIAC in 6.5 and .277 caliber. That's why I keep thinking .277 USA with 2.6 OAL is being developed. Big upgraded to the 5.56 Nato round. If .277 Wolverine, huge let down.

[marine6680]

SBR is another problem entirely.

The M4 I don't think of as an SBR, though it is technically. I think 11in and under for SBR.

16in is a better length for ballistics in 5.56 though. Below that and performance drops very fast.

The main infantry is not going to be going with an actual SBR... There is no bullet that can do SBR and intermediate range very well. You start running into issues on one end or the other as you try force that together.

You can do a bullet that works in a 16in barrel... That balances the needs pretty well.

If you need a true SBR, not just a carbine... You need a caliber well suited to that role.

5.56 works fine in 16-20in barrels, when you design the bullet well. There are plenty of examples of this.

Heck, it can work in a 11in barrel as well, but no bullet design that does so, is legal for use in combat.

[davidsog]

The M4 I don't think of as an SBR, though it is technically. I think 11in and under for SBR.

The M4's have a 14.5" barrel not 16". That is a civilian modification so they can sold legally and not require the tax stamp for a SBR.

The term "short-barreled rifle" means a rifle having one or more barrels less than sixteen inches in length and any weapon made from a rifle (whether by alteration, modification, or otherwise) if such weapon, as modified, has an overall length of less than twenty-six inches.

https://definitions.uslegal.com/s/short-barreled-rifle/

[davidsog]

They are changing the gas system from Carbine length to mid length.

Still keeping the 14.5" barrel.

https://partner-mco-archive.s3.amazo...1527866983.pdf

[RC20]

Maybe I misread it but I understand it is a development of the 6.8 SPC. It is been refined by the engineers or mucked up by big Army.

6.8 mm can mean anything. One of the reasons the 6.5s are doing well at a 1000 yards is the ELD and BC they get.

So until its fully defined, we don't really know what caliber 6.8 mm is. 7mm is .284 caliber. Should be .26x or the other.

What the shape is will determine how good a replacement it is for not just the 5.56 but the 7.62 as well (6.5 reaches out further and better than a 7.62 Nato)

[marine6680]

Yes... 14.5 is less than 16... Hence why I said "technically"...

It's an SBR from a legal civilian standpoint, it's just a carbine for the military.

When I think SBR, I m thinking 11in(ish) or less, not 14.5in. I also think short specialty firearms meant for close range door kicking as the primary focus.


And they should go up to 16in, it's not much, but that extra length does add almost 100fps, which improves performance.

The move to midlength should have happened a while ago, and with m855a1 it has become a necessity. That ammo has so much pressure that it kills rifles quickly. Midlength will help.

[Bartholomew Roberts]

The new 6.8 cartridge is not 6.8 SPC. It is a new cartridge developed by Textron. The case uses two different metals and it is supposed to offer a 20% reduction in weight.

Here is a picture of what is supposed to be SIG’s entries for the LMG and carbine:
https://www.recoilweb.com/sig-sauer-...on-142701.html

You’ll note both the carbine and LMG are based on 7.62x51 actions. Between that and the odd case design, I think you are looking at a cartridge with some significant differences from 6.8 SPC.

[stagpanther]

You’ll note both the carbine and LMG are based on 7.62x51 actions. Between that and the odd case design, I think you are looking at a cartridge with some significant differences from 6.8 SPC.

Yup--that plus the affirmation of backwards compatibility with both weapons and ammo production tells you right there that it's a 2.8" cartridge. Considering that it's being fielded as a potential short range, mid range sniper and long range weapon--probably means they are optimizing all the aspects of cartridge development to lighten it, make it more efficient and highly adaptable. Can't wait for the civilian issue one-use $10 a cartridge version!

You can almost hear Eugene Stoner laughing in his grave at the irony.

[davidsog]

For years, shooters chatting at the range or on the Internet have discussed what they "wished the AR-15 could do" and decried its diminutive 5.56 cartridge. With the advent of 6.8 SPC, fans of the "Black Rifle" are realizing it is now in a new category-- a real game-stopper and man-stopper. The soldiers of the Special Forces and the USAMU have opened the door to revolutionary capability in the AR-15; all shooters need to do is step through and start lighting primers.

http://demigodllc.com/articles/6.8-m...s-carbine/?p=7

This all started because of our experience with the poor lethality of 5.56mm.

The fact a couple of operators could wildcat a round in their garage to start the ball rolling towards getting a more effective round speaks volumes. It is silly to think that would be the final product.

The fact engineers could take that basic concept and improve it even further allowing existing magazines and brass cases to work with the new round and improve the ballistics is fantastic. That SIG found a way to overcome those weaknesses in 6.8 SPC original prototype is a good thing.

In the big picture, 6.8mm SPC is the basis for this new 6.8mm cartridge. The synergy of interfacing engineers and operators seems to work producing a much more effective product for the warfighter and the taxpayer.

[davidsog]

The new 6.8 cartridge is not 6.8 SPC.

It is based on the 6.8mm SPC. It is not an independent development but rather the result of operators finding the key to improving battlefield capability with as little disruption to logistics as possible. The original concept required using as much as possible already available in the inventory. 6.8mm SPC requires new magazines and new cartridge cases.

It did not happen in a vacuum and there is no cause for alarm. See the forest not the tree, lol.

[Bartholomew Roberts]

Originally Posted by davidsog

It is based on the 6.8mm SPC. It is not an independent development but rather the result of operators finding the key to improving battlefield capability with as little disruption to logistics as possible. The original concept required using as much as possible already available in the inventory. 6.8mm SPC requires new magazines and new cartridge cases.

If by based on the 6.8SPC you mean “uses the same diameter bullet”, then you are correct. Otherwise, it appears to be using a new technology case, is long enough it can no longer be used in a 5.56x45 action/magwell, and is designed to be fired at “velocities that can penetrate any known or existing body armor out there.” Source

I’m kind of pedantic, so when I need a completely different length action to shoot a new cartridge, I don’t really consider it to be “based on” that cartridge.

Going to logistics disruption, this is going to disrupt logistics a great deal more than 6.8x43. I’m guessing it will be expensive as well.

[rickyrick]

Wouldn’t make sense to try to make another 6.8 cartridge to fit the standard ar receiver. It would probably be financial ruin for anyone to try it.
This would need a different rifle to even be worth the trouble. If the army wants s more powerful rifle it’s going to require a bigger cartridge, which will require a heavier gun, heavier cartridge and more recoil.
I feel most of the good things that can be stuffed into a standard AR reciever, have already been tried. Whatever they come up with will still be limited by military specs and something civilian will still be far superior.