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!!!