Home Forums Hunting & Shooting Ask The Gunwriters New Army cartridge announced to replace the 5.56 in service rifles and SAWs

I just read an announcement that the Army would be adopting a high velocity 6.8 Cartridge for the new service rifle and squad automatic weapon.

Does anybody know anything about it? Is this just a lead free light weight bullet out of the existing 6.8 SPC in polymer case ammo?

One article I read said it was the 6.8 SPC loaded 20% hotter than normal. Sounds SPC II to me. They are wanting it on a totally new rifle and LMG platform.

What is a SPC II? I have seen that term but am not sure what it means?

SPC II = An update to the chamber dimensions of the original 6.8 SPC.

According to Wikipedia:
"There are several different chambers for the 6.8 SPC which yield different results. They are:

Original Murray 6.8×43 ERC developed in 2002.

The Remington SAAMI submitted specifications. It was supposed to have a 1.3 mm (0.050 in) freebore, 45° cone angle, 7.1 mm (0.278 in) ⌀ freebore. The reamers and PTG prints had an 80° neck to freebore cone angle, which was a result of a mistake in the reamer drawing submitted, and was never corrected by the reamer maker or Remington during the process of tooling up for the testing protocols that eventually drove the SAAMI submission.

SPC II is current standard chamber used by most barrel manufactures. It has been said to be very close to the original Enhanced Rifle Cartridge Program chamber. It has a 2.5 mm (0.100 in) freebore, 45° cone angle, 7.1 mm (0.278 in) ⌀ freebore, 7.84 mm (0.3085 in)neck.

..."

Also Saami specs for 6.8 SPC is 55,000 psi. A 20% increase would be 66,000 psi. This is above the highest sammi max of 65,000 psi.

This is based on brass cased ammo. The rules may be different for the new polymer case stuff the military is looking at. But for the life of me,I don't see any polymer being tougher than brass.

I did read that ATK has developed a high velocity load for the 6.8SPC that uses a 90 grain Gold Dot bullet which is a bonded core bullet developed specifically for the cartridge that is being adopted by various military units around the world.

More importantly, can we neck it down?

A fast twist 223 AI version would be cool. I think somebody already did one. Federal or Nosler or something.

Or maybe a Creedmoor version?

Actually it sounds a lot like the 276 Pederson that was being experimented with before World War Two. Gerneral Hatcher said the terminal effects of a FMJ bullet from that one were lackluster.

The reason he said that was they wanted to use up the left over10 bazillion WW I 30/06 cartridges rather than start a new run of a new cartridge.My Uncle was working at The Armory and was testing the M1 with the 276 and thought it was an excellent cartridge.He used it at Camp Perry to win a chit load of matches.

General Hatcher did write in his book about the subject that he did like a 256 experimental cartridge they were looking at during the same time. He actually favored the 256 and said it's terminal effects were very good.

He hunted with a 257 Roberts based on his experience with the experimental 256.

Not gonna happen....more keyboard tomfoolery.

Correct.

And the 6.8 cartridge they've been discussing is plastic cased, telescoping like these. nothing to do at all with the SPC.

Agitator!!

You might check with the guys on this forum.
https://68forums.com/

Yea, a 25 SPC would be nice...

Nosler already did: The 22 Nosler. 25% more case capacity over the .223 Remington with Nosler's claims of +300 FPS.

yup. Have a 6.8 necked down to 6.5 in AR platform (pretty sure I got it from a member here). Check out ar15performance.com. Does some good work, great CS and a good guy.

I'd really like to see what they come up with. Some of the numbers I have seen in print make me think that either someone doesn't have
clue OR there is a total new technology on the horizon. The velocities I have seen published 6 months ago would beat a 270 Weatherby Mag badly. Like 800 FPS badly.

If this is not a misprint I am left with the questions of:
(A) how are you going to get a cartridge holding that much powder into a light weight assault rifle?
and (B) how are you going to keep it from burning up with rapid fire and full auto fire?

I think the 6.8SPC is quite a good round on it's own merits as a combat round, but the numbers that came from the Army's web-site news clip made the 6.8 SCP look like a primer in comparison to what they printed.

Speeds asked for were well over 4000 FPS with 115 grain bullets.

As I said, I am just standing by to see what they come up with. The overview is a new weapon and a new cartridge. It's possible the new weapon is nothing like an M16/Ar15 at all.

Is this thing going to be a "space gun"?

Insanity!! It must be a 6.5 or its not any good!!!

Did the Army "Catch the Gay" by going with a 270? Say it's not so. Where is Ingwe when we need him?

It's going to be called the 6.8 creegrenvalkitherby MAGNUM +p tactical, in civilian form.

https://www.militarytimes.com/news/...ll-make-soldiers-marines-a-lot-deadlier/

It is hard to fathom how the muzzle energy for this round can be real. If so we are talking revolution and not evolution.

Well I bet the hype is more powerful than the cartridge!

I can’t understand why they would go 6.8 instead of 6.5...

John

They tested all of the calibers and the article states that from an M-4 out to 500 yards the 6.8 proved the best performer..

The AMU SOF etc figured that out when originally coming up with the 6.8 SPC

Mike

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.”

I stumbled on a site yesterday called Tatical life. They had an article on it.

The question is will the cartridge be polymer cased or telescoping polymer based? I am pretty sure it will be one of the above.

It does appear that it will be a 6.8 that will shoot light for caliber bullets at higher pressure and velocity than the 6.5 SPC II.

They are actually going for 270 ballistics in a platform no larger or heavier than current AR rifles.

It is ironic that they went with a .277 caliber when the best BC bullets are 6.5 or 7mm. But the fact that they are using light for caliber bullets at distances of 500 meters or less negates any advantage of higher BC bullets in 6.5 or 7mm.

It appears that the military went with the Campfire concensus,within 500 yards,nothing really beats a 270.

To Quote them :

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

Now I would point out that the test done in 2006 showed the 6.8 to beat the other rounds overall, but this new .277" bore round didn't exist in that test, so I can't put any stock in that test. it was a kick in the crotch for the worshipers of the 6.5 Grendel, but that is how it shook out. It must be remembered that the test had certain perimeters most of which didn't revolve simply on ballistic flight characteristics or even energy.

The rounds had to fit in an M-16 magazine and M-4 type carbine.
The idea was to come up with a round that was better at killing or incapacitating enemies out to 400 yards better then the existing 5.56 NATO round.

Some rounds like the Grendel did "fly better" then the 6.8 SPC out past 400 meters but with the bullets available to test in that year the 6.8 out killed the 6.5 at every range when tested at Brag and Benning and later at Marine Corps Camps in Va. 5th Special Forces did a pretty extended deer hunt with the new rifles and that was kept away from the public for about 6 years to keep the libs from bitching about it.

The 6.5 MM rounds did shoot flatter and buck wind a little better but that was not what the Army was looking for. To quote General Krulak "we don't need a long rage rapier, we need a close to mid range hammer. Our current 7.62 and even our 5.56 already do good work at long range"

Another kick in the crotch for the 6.5 Grendel in 2006 was the nonavailability of good magazines that held the required number of rounds and still functioned at 100% reliability. The 6.8 mags they started with worked fine.

Now that the Army is thinking about a total replacement or both weapon and round, I think the 2006 test may be invalid.

What ever new round they pick need not fit an M-16 mag anymore so it seems.

The last rifle the USA adopted that was made in concert with the round before the AR-15 (re-named the M16) was the 1903 Springfield. The Springfield and the 30-03 and 3006 round were developed together. The original AR15 prototypes were made in 222 Remington.

The M-1 Garand was re-designed to use the 30-06. Garand originally made the rifle around the 275 Peterson round.
The M14 was a re-work of the basic M1 Garand idea, and the 308 winchester (7.62 NATO ) was simply a 30-06 shell with the shoulder moved back to the existing powder charge so the air space was eliminated.

But it may be that the new rifle is going to be designed at the same time as the new round. Like guns were made in the late 1800s and very early 1900s. That may be very interesting. Instead of a re-work of existing weapons, this time they may start at "ground zero" and simply make the whole system together. That requires a lot more money, but the result is likely to be superior.

+1

Cool, wonder which generals have a financial interest in the company slated for supply.

I remember that. My understanding at the time was that it was all about the bullets. It wasn't something magical about the bore diameter, it was that the bullet compared weren't identical in construction.

I could be wrong, but I have a hard time believing that 3 tenths of a millimeter could make a measurable difference in killing.

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Absolutely correct. Bullets are the key here, not shells shapes. In the early days of the debate between those that like the 6.8SPC and those that like the 6.5G, the 6.8 had a number of good quality hunting bullets available and the 6.5 had about 1. The 125 grain Nosler Partition.

Since that time the 6.5 has gained a lot of popularity and there are quite a lot of hunting bullets that work well in the 6.5G now days. The largest reason the 6.8 out killed the 6.5 was the fact that 10-13 years ago almost all the kills made with the 6.5 were made with target bullets and the 6.8 was being used with hunting bullets. This coupled with the fact that the larger bore size did give a bit larger diameter wound channels. Any bullet when it expands to perfection goes to 2X it's unfired diameter. That's the "perfect standard". So a .277 expands to .554 and a 264 expands to .528 in the 'perfect world".

In the real world however, the target bullets of the 6.5 were not expanding reliably at all, often bending or breaking up and with a great numebr of wounds veering off to give wound channels in deer where the shooter didn't want to make them. So I think the deck was stacked against the 6.5 from the onset.

Personally speaking, I prefer the 6.8SPC to the 6.5G, but I don't say it's vastly better.

I have no need or desire to own a mid-power cartridge that flies well enough to make hits at 800 yards. I don't shoot that far at game... ever. I can, but I refuse to do it. I shoot at 1000 and 1200 fairly often at non-living targets, and I know how to do it. I do it pretty well, but I personally think it's unethical to do it on game animals.

I have been involved with the 6.5 cartridge since it first came out and I was making cases out of 30 Remington and even 30-30s with the rims turned off and a groove machined into the head. So you can say I have been around it from the get-go. But I also got interested in the 6,.5 Grendel not long after that, and I have made and used them, several times too. Overall I rate the 2 cartridge as being similar.

I have seen faster kills with the 6.8 at closer ranges, out to about 200 yards then I have with the 6.5G. At 250 out to about 350 I see no difference at all when used on deer and antelope. At 400 and out, the 6.5 seems to do well and maybe a bit better then the 6.8. So I have a good respect for the 6.5G but after making many of them, and using them for a few years, I sold them all and kept my 6.8s. That's just my personal preference.

I like the fact that MOST of the kills I have made with my 6.8s have been "bang-flops" So far I have killed 36 head of game with my 6.8s and of them all, only about 5 were not "bang-flops"

I have never seen a long run with a deer or antelope shot with the 6.5G, (most go about 15 to 20 yards) but I have only seen one "bang-flop" with it, so this is why I say what I say. I agree with the Army and USMC in their findings.

I saw it 2 more times just 2 months ago. My friend Randy came out from Nevada to hunt antelope and he brought a 20" 6.5 G. He made 2 excellent hits on 2 antelope with 123 grain Hornady bullets, and neither went more then about 20 yards after the shots, but neither one dropped at the shot either. Randy also owns several 6.8 SPCS and he is the only man I personally know that has killed more game with the 6.8 then I have, (Last count he had killed 38 head of game with his 6.8s) and he also tells me most have been 'bang-flops"
The 6.8 seems to drop the game a bit faster at short to mid ranges. (which constitutes about 90% of the kills in the real world) At room clearing distance out to about 200 or maybe 250 the 6.8 SPC just kills faster.

If I were limited to one auto-loading rifle for hunting my 1st choice would be an AR-10 size light weight (8.5 pound) rifle in 7-08.

If that was not available and I wanted to stay in the AR15 size I would go with the 6.5G because it kills well enough for me to not worry about long blood trails, and it does out-fly the 6.8 at the ranges from about 375 to 500 yards.

But I can own more then one. And I do.

So I choose the 6.8SPC and if I want something for longer shooting I own a 25-06 a 6.5X54 M/S, a few 270s and also several 30-06s, two 308s, an 8X57, a 300 Magnum, a 9.3X62, a 9.3X74R and a 375H&H, ALL of which tromp on both AR cartridges badly.

So the idea that the small gain I can see for the 10% of the shots I take with the AR15s by using the 6.5 over the 6.8 is not based in reality. The 90% favor the 6.8.

But for someone that wants a "deer gun" in an AR, and doesn't have a safe full of other options, the 6.5 G may be the round that covers the bases a bit batter. You really can't go far wrong with either one.

I think the rimless 6.8 case makes more sense in a straight magazine. I am puzzled by the 6.8 diameter. I wondered if it might have been to avoid any legal stuff with the already SAAMI 6.5 Grendel.

my thought process was that existing 100 gr partition in 6.5 was better than any light 270 bullet (varmint mostly)

little thinner, little lighter for same SD, easier to make velocity on smaller powder column.

So easy now to buy a grendel barrel or rifle and dies and brass, compared to same for a wildcat 6.5SPC.

Mini Howa and be done with it, or one of many AR manufacturers.

This stuff is wildly amusing, and perfectly typical of those basing decisions on emotion and popular sentiment rather than cold logic. Look at the evolution of US combat arms since WW2 and you might realize we have a history of using the last war's weaponry for today's war. Simple solution is to accept the idea that battle field landscape in the future is uncertain and it might be useful to have 2, possibly 3 different platforms to equip our troops with. Cover the terrain, equip the mission and get it done.

And while we're at it, perhaps we can get over this idea that shorter barrels are better.

Well said, Dan.

my comments were related to the use of the cartridge for civilian purposes including plinking, target shooting and hunting.

Military needs trump all that, clearly. Hard to know if weapon systems could or should keep up with our culture as it changes. . Assume that culture within military does adapt to a) hardware they have and b) opponents tactics. If there is time.

Dan's point is well taken, procurement often reflects the needs/wants of the last conflict.

Maybe the length of the current war has allowed for appropriate adaptation.

I don't believe the good Dr. Roberts for a second, either .270 is a magical bore, or it's just not true. Maybe the specific projectiles tested performed the best in their test according to Dr. Roberts' evaluation of the results. But nothing magically "optimal" about 6.8 vs 6.5 or 7mm diameter bullets.

6.8 SPc would be a bad joke for a general issue cartridge to replace the 5.56, so I assume they have something totally different up their sleeve, like a new CT or polymer-cased round.

It has absolutely nothing to do with 6.8 SPC. Nothing.

The 6.8 performed the best in the initial terminal ballistics work in a specific situation/comparison. It has nothing to do with the 6.8 bore diameter.

The NGSAW/6.8 whiz gun doesn’t exist, won’t exist, has cost billions in failed projects, and will cost billions more. The technology does not exist to do it.

To 6mm ? It seems the guys at Predator Masters are doing it with good results.

kwg