I did not think that I needed to add the qualifier "recent" or "designed in the last half-century".  I was aware, for example that the shoulder angle is similar, but not equal to, that of the 7.62x39 cartridge.   To be more precise then, upon reviewing SAAMI approved cartridges, the .264 USA has an unusually gentle shoulder angle for an American cartridge designed in the last 50 years,  with the exception of the 7-30 Waters which, for reasons known only to the designer himself,  uses a shoulder angle of 34°24'. 

BTW, this includes cartridges based on older case designs that utilize the shoulder angle of the parent,  like the 25-06 Remington which was approved in the 1960's.

I agree on this idea of funding development phases that merge the best of what we had presented into a single best of everything final product.

We probably also need better baseline funding for incremental improvements and r&d.

It seems like a criminal waste to not keep funding both sig and Lonestar/tv to improve what they have and even to give each team a copy of the other teams work so they can both make improvements.

I think if anything this particular competition has shown us that the way we're handling development and implementation is wildly suboptimal and that in order to really get the most out of what we have we need to do things differently.

nincomp said:

I did not think that I needed to add the qualifier "recent" or "designed in the last half-century". 

To be more precise then, upon reviewing SAAMI approved cartridges, the .264 USA has an unusually gentle shoulder angle for an American cartridge designed in the last 50 years...

Seeing as how this is not the Sporting Arms and Ammunition forum, I thought that you meant it's "unusually gentle" for US military cartridges.

The 17.5-degree shoulder of the .264 USA is the same as on the .30-06, and only slightly gentler than the 20-degree shoulder of the 7.62 NATO.

BTW, the only comment I found about .264 USA being "amenable" to use of polymer cases is this speculation on TFB:

"Not only has the .264 USA possibly been designed specifically for composite cased ammunition, or at least with it in mind..."

POTD: The Polymer Cased .264 USA -The Firearm Blog

Since that says nothing about .264 USA case shoulder angle, I'm curious as to the source where it was suggested.  Link?

I have to question how such a small difference in shoulder angle (relative to 7.62 NATO) is likely to be significantly better.

https://twitter.com/JakOSpades/status/1522505470598168577?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1522505470598168577%7Ctwgr%5E%7Ctwcon%5Es1_&ref_url=

design of sig lmg to xm250 has slight differences. 

I really wonder how much long term durability this gun is going to have. The 6.8NGSW is substantially hotter than 7.62NATO, and the XM250 is extremely light weight. At this point I wouldn't be surprised if the design picks up several lbs in the next few years as it transitions to adoption then A1/A2/etc forms.

Apsyda said:

At this point I wouldn't be surprised if the design picks up several lbs in the next few years as it transitions to adoption then A1/A2/etc forms.

The Sig MCX 5.56 started off ~2015 as a beautifully balanced 6lb rifle. I held it when it was debuted at SHOT and though 'wowza!'

Well it got taken off the market, multiple versions later the 'MCX Virtus Patrol' is now a hulking 7.9lbs....it went from the lightest piston 5.56 in the world to one of the heaviest 5.56 rifles in the world. 

So I could absolutely see the NGSW's gaining weight over time. 

The original virtus was In many ways the inspiration for my current AR pistol build.

So much so that my 11.5" bbl foxtrot Mike bufferless AR is actually going to wind up sporting a sig folding buffer tube knuckle (the sig folding tube to picatinny knuckle is gorgeous and gas very nice positive lockup) mated to a tailhook mod2 assembly.

Picked up a PA dot and magnifier which sit on a lower 1/3 cowitness riser and has the magnifier folding left along with the brace.

Unlike virtus it's a DI unit but it took a lot of cues from what sig did there. It should weigh somewhere between current virus weight and original virtus weight all up and my ammo of choice will fragment out to 300 meters from an 11.5" tube.

We desperately need to get back to light handy guns if for no other reason than so we can put 3 pounds of shit on them and ONLY have them weigh as much as a loaded Garand all up.

https://www.youtube.com/watch?v=GEf3ZlUkOCg

garand thumb vid yay