New Military Cartridge - 6.8x51mm

[jwc007]

Actually, though conceptually just a 7.62x39 necked down to 6.5mm, Bill Alexander redesigned the 6.5 Grendel cartridge case specifically to fit the AR15 platform. No “banana clips” for the 6.5 G. The 6mm ARC is basically a necked down 6.5 Grendel. Which is better? Time will tell, but the 6.5 G has a significant jump start in popularity and affordability, at least in the commercial market. Serbia has adopted the 6.5 G in the DMR role, so I’m sure their ammo plants can fill the gap left by Russia, if they want to make some money. From what I’ve seen, the 6.5 G holds a slight edge ballistically over the 6.8 SPC.

Actually, I would have loved the x39 simply necked down to 6.5 so that I could use all my AK mags for an improved caliber.

The US Military definitely needs an upgrade over the diminishing effectiveness of the 5.56. They already looked hard at the 6.8 SPC — and dropped it. Expect them to do the same with the 6mm ARC. US Military small arms ordnance — always expect them to do the stupid thing (stick with the 5.56) and waste billions of taxpayer dollars in the testing and re-testing process. Thanks

Look like the USA DOD has reconsidered the 6.8 SPC and adopted it.  I would have preferred either the 6.5 Grendel or 6mm ARC, myself.  Wonder what NATO thinks of this?
See Link:  https://www.yahoo.com/news/army-picks-replacement-m4-saw-230105091.html

Trouble with this article however is that there is no distinction made between the 6.8 SPC and 6.8x51mm.  Looks like the 6.8x51mm may be it.

Congressional approval of the $$$ for this however is still pending, so nothing is really carved in stone, but likely to happen.

[RSR]

Actually, though conceptually just a 7.62x39 necked down to 6.5mm, Bill Alexander redesigned the 6.5 Grendel cartridge case specifically to fit the AR15 platform. No “banana clips” for the 6.5 G. The 6mm ARC is basically a necked down 6.5 Grendel. Which is better? Time will tell, but the 6.5 G has a significant jump start in popularity and affordability, at least in the commercial market. Serbia has adopted the 6.5 G in the DMR role, so I’m sure their ammo plants can fill the gap left by Russia, if they want to make some money. From what I’ve seen, the 6.5 G holds a slight edge ballistically over the 6.8 SPC.

Actually, I would have loved the x39 simply necked down to 6.5 so that I could use all my AK mags for an improved caliber.

The US Military definitely needs an upgrade over the diminishing effectiveness of the 5.56. They already looked hard at the 6.8 SPC — and dropped it. Expect them to do the same with the 6mm ARC. US Military small arms ordnance — always expect them to do the stupid thing (stick with the 5.56) and waste billions of taxpayer dollars in the testing and re-testing process. Thanks

Here's C Products 26 round 6.5 Grendel Duramag: https://gunmagwarehouse.com/duramag-ar-15-6-5-grendel-26-round-stainless-steel-magazine.html



Looks pretty banana to me.  Recall earlier C Products being Robinson's recommended 7.62x39 mag...

There's nothing wrong w/ 5.56 in support troop role, much like the M1 carbine in WW2.  And remember the M16 was first adopted for US Military use by the Air Force... 
It can be marginal as frontline infantry weapon in some instances; however, if foot-borne troops on extended patrol with limited ability to resupply, the fact that a round of 5.56 weights about as much as a round of 9mm pistol ammo, does arguably serve to increase firepower -- and that's before we account for .308 mags for instance having 20 rounds at approximately 40% more weight to 5.56's 30 rounds.  Most rounds fired in combat by infantry are for suppression, not precision aimed fire.

To that end, I also think 5.56 is capable in SAW role for foot-borne troops, especially since many marginal barriers can be pulverized with enough rounds, but also that grenade launchers can also be brought to bear for barrier penetration/concentrated fire.
That said -- for mounted troops, I think something 6.5 to 7mm caliber would be an improvement over 5.56, and possibly even .308...

[RSR]

Actually, though conceptually just a 7.62x39 necked down to 6.5mm, Bill Alexander redesigned the 6.5 Grendel cartridge case specifically to fit the AR15 platform. No “banana clips” for the 6.5 G. The 6mm ARC is basically a necked down 6.5 Grendel. Which is better? Time will tell, but the 6.5 G has a significant jump start in popularity and affordability, at least in the commercial market. Serbia has adopted the 6.5 G in the DMR role, so I’m sure their ammo plants can fill the gap left by Russia, if they want to make some money. From what I’ve seen, the 6.5 G holds a slight edge ballistically over the 6.8 SPC.

Actually, I would have loved the x39 simply necked down to 6.5 so that I could use all my AK mags for an improved caliber.

The US Military definitely needs an upgrade over the diminishing effectiveness of the 5.56. They already looked hard at the 6.8 SPC — and dropped it. Expect them to do the same with the 6mm ARC. US Military small arms ordnance — always expect them to do the stupid thing (stick with the 5.56) and waste billions of taxpayer dollars in the testing and re-testing process. Thanks

Look like the USA DOD has reconsidered the 6.8 SPC and adopted it.  I would have preferred either the 6.5 Grendel or 6mm ARC, myself.  Wonder what NATO thinks of this?
See Link:  https://www.yahoo.com/news/army-picks-replacement-m4-saw-230105091.html

Trouble with this article however is that there is no distinction made between the 6.8 SPC and 6.8x51mm.  Looks like the 6.8x51mm may be it.

Congressional approval of the $$$ for this however is still pending, so nothing is really carved in stone, but likely to happen.

Thanks for sharing -- hadn't seen that.

Sig calls it a "SIG FURY 6.8 Common Cartridge Ammunition" in its press release:
https://www.sigsauer.com/blog/us-army-selects-sig-sauer-next-generation-squad-weapons-system

I think it's AKA as ".277 Sig Fury" best as I can tell.  Here's Guns and Ammo on it from earlier this year -- necked down .308: https://www.gunsandammo.com/editorial/277-sig-fury-cartridge/457153

80k PSI seems crazy high -- reading on in the article it goes into.  Wonder what barrel life will be with this vs .308?  Certainly shortened.  6.5 Creedmoor is roughly the same as .308 at low 60ks IIRC.  2 piece case also looks expensive...

[MeatAxe]

Actually, though conceptually just a 7.62x39 necked down to 6.5mm, Bill Alexander redesigned the 6.5 Grendel cartridge case specifically to fit the AR15 platform. No “banana clips” for the 6.5 G. The 6mm ARC is basically a necked down 6.5 Grendel. Which is better? Time will tell, but the 6.5 G has a significant jump start in popularity and affordability, at least in the commercial market. Serbia has adopted the 6.5 G in the DMR role, so I’m sure their ammo plants can fill the gap left by Russia, if they want to make some money. From what I’ve seen, the 6.5 G holds a slight edge ballistically over the 6.8 SPC.

Actually, I would have loved the x39 simply necked down to 6.5 so that I could use all my AK mags for an improved caliber.

The US Military definitely needs an upgrade over the diminishing effectiveness of the 5.56. They already looked hard at the 6.8 SPC — and dropped it. Expect them to do the same with the 6mm ARC. US Military small arms ordnance — always expect them to do the stupid thing (stick with the 5.56) and waste billions of taxpayer dollars in the testing and re-testing process. Thanks

Here's C Products 26 round 6.5 Grendel Duramag: https://gunmagwarehouse.com/duramag-ar-15-6-5-grendel-26-round-stainless-steel-magazine.html



Looks pretty banana to me.  Recall earlier C Products being Robinson's recommended 7.62x39 mag...

There's nothing wrong w/ 5.56 in support troop role, much like the M1 carbine in WW2.  And remember the M16 was first adopted for US Military use by the Air Force... 
It can be marginal as frontline infantry weapon in some instances; however, if foot-borne troops on extended patrol with limited ability to resupply, the fact that a round of 5.56 weights about as much as a round of 9mm pistol ammo, does arguably serve to increase firepower -- and that's before we account for .308 mags for instance having 20 rounds at approximately 40% more weight to 5.56's 30 rounds.  Most rounds fired in combat by infantry are for suppression, not precision aimed fire.

To that end, I also think 5.56 is capable in SAW role for foot-borne troops, especially since many marginal barriers can be pulverized with enough rounds, but also that grenade launchers can also be brought to bear for barrier penetration/concentrated fire.
That said -- for mounted troops, I think something 6.5 to 7mm caliber would be an improvement over 5.56, and possibly even .308...

Nobody who knows better uses C-Products mags for 6.5 Grendel. They’re great for 7.62x39, but those in the know use E-lander mags for 6.5 G, which are pretty much straight up and down. Same with 6.5 G AKs, the only mag to use is Csspecs, which are straight up and down. C-products 6.5 G mags don’t have a great reputation. They look pretty much like a x39 mag, repurposed for 6.5 G.

As far as continuing to use 5.56 for the foreseeable future, I guess the US will have to get into a peer on peer war with an enemy with effective body armor before we upgrade, which is about par for the course with US Ordnance.

[RSR]

Interesting vid on NGSW:

https://www.youtube.com/watch?v=FruM2IwvRq4

[jwc007]

Why doesn’t a moderator just put this somewhere else?

B/c the mod raised the NGSW on a thread where there was a caliber/ergo/reliability/ballistics/etc. discussion regarding the Vz58 and alternatives that you described as interesting -- and the vid I shared is a continuation of that discussion and trade-offs for anyone where cares to watch it?

After some thought, the subject really does deserve it's own  thread, so here it is. 

[Auslander]

FYI:

There is another good thread here:  https://czfirearms.us/index.php?topic=118905.0

The fact of the matter is that we have very little information; but, what we do have has a lot of people scratching their heads.

In terms of a replacement for the M240 and M249, the platform seems to have a lot of positives and kinda makes sense.  Its lighter than both (from what I can find) and the ammunition is a little lighter than .308 and has better long range capability.  Military already keeps different supply chains for both those platforms so you could consolidate linked ammunition type (aside from the MG338 and .50).  What doesn't make sense is the chamber pressure.  For the military 6.8X51, I'm seeing repots of 88K psi.  I may be wrong and they invented some new type of barrel material, but otherwise, guys will have to carry barrels on their backs like a quivers of arrows.  There are a lot of short-action cartridges with similar ballistics that do what they do with less pressure.   

In terms of a M-16 derivative replacement....I'm highly skeptical.  The rifle, particularly kitted out with the new optic and suppressor, will be HEAVY.  Like 12 to 13 lbs heavy....  Ammo is heavier and more bulky than 5.56 and recoil looks to be much worse.  There is a reason the military went with the M16 and not the AR10...  Add all that to an already heavy loadout.......  I get it, we need to be ready to fight a peer adversary and the Chinese are using a 5.8mm round that slightly outclasses the current 5.56.  Something like the 6.8SPC or 6mm ARC starts to make sense.  For that matter, make a hybrid 6.8 SPC and shoot it with insane pressures.   

6.8X51 for everyone? Size requirements and PT standards are going to have to change.   

https://www.cnas.org/publications/reports/the-soldiers-heavy-load-1#:~:text=U.S.%20ground%20troops%20today%20carry,%2C%20batteries%2C%20and%20other%20gear.

DMR and specialized combat roles - OK, but some of our guys in specialized roles are already using AR-10 sized rifles chambered in 6.5 Creedmore. 

Of course, I'm a guy that still thinks the 30-06 is a perfect cartridge. I reckon I'll keep scratching my head.  We'll know more by 2024.       

[RSR]

FYI:
In terms of a replacement for the M240 and M249, the platform seems to have a lot of positives and kinda makes sense.  Its lighter than both (from what I can find) and the ammunition is a little lighter than .308 and has better long range capability.  Military already keeps different supply chains for both those platforms so you could consolidate linked ammunition type (aside from the MG338 and .50).  What doesn't make sense is the chamber pressure.  For the military 6.8X51, I'm seeing repots of 88K psi.  I may be wrong and they invented some new type of barrel material, but otherwise, guys will have to carry barrels on their backs like a quivers of arrows.  There are a lot of short-action cartridges with similar ballistics that do what they do with less pressure.       

Yes, I don't get it as LMG cartridge.  Those pressures will burn through barrels...

And FWIW and AFAIK, SOCOM is already fielding Mk48 LMGs in 6.5 CM that were easily upgraded from .308...
https://www.thedrive.com/the-war-zone/28138/u-s-special-operators-will-soon-be-using-this-6-5mm-assault-machine-gun

Basically, to me -- this comes down to Sig having excessive influence...

[jwc007]

https://youtu.be/Nm64SgA2M3s

[RSR]

https://youtu.be/Nm64SgA2M3s

That vid's over a year old and discusses concepts that weren't adopted in how recoil is mitigated.

Here's a Dec 2021 video by the same dude showing him shooting both suppressed and unsuppressed versions @ 2:15: https://www.youtube.com/watch?v=OSE1VftyHYo

No major overall recoil differences between the two that I see...  Suppressed looks like it might extend recoil impulse (or just extra weight of longer barreled gun) but still about the same amount of force based up his rearward movement.