Traditionally, small arms ammo relied on neck tension to keep the bullet in place, but if you look at medium-caliber ammo, the case neck is very short, look at the 25x137 mm or the 30x173 mm case.

I think that conventional ammo could be made with a very short neck (so short that it's close to non-existant), and that you could make "neckless" ammo configuration even with brass or steel case, with minimum modification to existing manufacturing process.

gatnerd said:

Which is nuts, as pretty much any caliber with a Fire Control Unit would have dramatically more hit probability. And there are any number of lighter recoiling VLD cartridge configurations that could exceed 7.62 lethality.

That's right, but even with a FCU you have errors, and with a high velocity round with a good BC bullet you could accept more errors than a lower velocity round with a crappy BC.

Anyway, you're right that replacing the 7.62 mm NATO with the 6.5 mm Creedmoor or the .260 Rem (or any other other cartridge like the .224 Valk, 6 mm ARC or 6 mm Creed) will already allows to achieve 80% of the single shot effectiveness gain that the 6.8 mm will bring.

EmericD said:

That's right, but even with a FCU you have errors, and with a high velocity round with a good BC bullet you could accept more errors than a lower velocity round with a crappy BC. Anyway, you're right that replacing the 7.62 mm NATO with the 6.5 mm Creedmoor or the .260 Rem (or any other other cartridge like the .224 Valk, 6 mm ARC or 6 mm Creed) will already allows to achieve 80% of the single shot effectiveness gain that the 6.8 mm will bring.

Well sort of like we discussed earlier on designing for hit probability, using that wonderful software of yours. 

Absent the armor requirement, 'NGSW 2.0'cartridge design could be based on:

-Maximizing hit probability within the FCU framework 

-Increasing fragmentation range for EPR beyond 7.62 

-Minimizing recoil and cartridge weight while fulfilling above requirement

-Maximizing magazine capacity / belt density 

-Using NGSW 1.0 technology to achieve all of the above 

Or 570 Supercruise, which would allow you to achieve three times the single shot effectiveness.

Put a crown of thorns on me and hang me up to dry, I'm a prophet, baby!

gatnerd said:

Well sort of like we discussed earlier on designing for hit probability, using that wonderful software of yours.  Absent the armor requirement, 'NGSW 2.0'cartridge design could be based on: -Maximizing hit probability within the FCU framework  -Increasing fragmentation range for EPR beyond 7.62  -Minimizing recoil and cartridge weight while fulfilling above requirement -Maximizing magazine capacity / belt density  -Using NGSW 1.0 technology to achieve all of the above 

i.imgur.com

570 supercruise also has it's stupid short time of flight to any given range which in conjunction with the FCU's will make it even more death laser like than even those charts suggest

I just thought about bullets and sabot, I think I have an idea to significantly reduce the cost of this kind of ammo. I will send you an e-mail next week.

Unfortunately, I still have no idea on how to avoid sabot slippage and in-bore yaw...

EmericD said:

I just thought about bullets and sabot, I think I have an idea to significantly reduce the cost of this kind of ammo. I will send you an e-mail next week. Unfortunately, I still have no idea on how to avoid sabot slippage and in-bore yaw...

Interesting. I'll be excited to read that.

I just followed "best practices" for the APDS tank ammunition of yore. That means I kept the sabot bearing surface well ahead of the CoG, and I used another little trick to keep the projectile locked in rotation.

"Quintus O:  ... And, likewise, I think TV's ammunition is the betting horse here, at least from a technology standpoint. Textron seems to have had the most favor politically from the outset. "

Textron does seem to be rather good at playing "The Game"...

The Textron/AAI/UIC, whatever they feel like calling themselves this time around has been involved in US smallarms development since Project salvo and SPIW programs in the 1960's. In fact one would be hard pressed to find a US small arms program they were not a part of on some level. As AAi they took part in the Future Rifle program begun in 69'. In 86 they were naturally part of the ACR program. At LSAT startup in 2004 they were there. And now as Textron for the NGSW.

Hundreds of millions have been poured into these programs over the years. With no doubt a few tens of millions going Textron/AAI/UIC's way. But they are playing the game, not making the rules. In all the various small arms programs not a single rifle designed by anyone has taken the field.

Mostly, I attribute that to two things:

1:  The military never really having a clear plan about what they actually want. (sometimes asking for conflicting requirements)

2:  And the industry/institutional investment in the 5.56/AR15 platform. Lots of politics...