NGSW the next steps
In April, The U.S. Army announced the award of a 10-year firm-fixed-price follow-on production contract to Sig Sauer, Inc. for the manufacture and delivery of two Next Generation Squad Weapon variations (the XM5 Rifle and the XM250 Automatic Rifle) and the 6.8 Common Cartridge Family of Ammunition.
I was one of several key people that helped initiate the Next Generation Squad Weapon program. More about my past efforts on this program can be found in these links .... The Origins of NGSW | Plumb Precision Products LLC and.... "New Calibers, the Fight to Come" by Frank Plumb - Soldier Systems Daily .I highly suggest you read these 5 year old articles before drawing any conclusions on this article.
The blogosphere and Facebook groups show a lot of discontent over the acceptance of the XM5. There is much less angst over the XM250. Which is to be expected considering we have been lugging the M240 for decades.  The XM5 uses a SR25 type magazine which implies a comparison to the M14. While we are emotionally comparable to the Vietnam generation’s M16 adoption, there are significant differences.
The Generals and Officers, senior civilian leaders, and DoD developers’ intentions have the right focus. They seek to provide the American Ground Combatant the best possible small arms systems. Understand the administrative and logistical efforts necessary to make NGSW happen. The Late Senator John McCain once told me “it (NGSW) costs less than one Virginia class Submarine, it is at best a low priority budget side item”. The Pentagon is focused on submarines, new fighter aircraft, and other major end item programs. A new shiny gun does not get much airtime in congress.
Senators Cotton and Ernst, both veterans, have been staunch advocates of this program. The Office of the Secretary of Defense protected the funding. Then the tireless effort of the developers and managers kept this program on track. This program faced the massive entrenched institutional biases and cultural dogmas that killed much less ambitious programs. NGSW is a very ambitious program that will have far reaching consequences for all U.S. and NATO ground combatants.
We must consider some of capability of the program is classified. We need to be cognizant while evaluating the effects of this program, that we do not have all of the information.
When looking at NGSW remember this most important element; this weapon is at the beginning of the development cycle not the end. The XM5 is at the very beginning of its life. It has not had a chance to unlock its potential. Refinements will come. Now is the time for those who develop and enhance a system to get to work.
I have always believed solutions must fit three primary parameters. Something we field must; improve performance, support doctrine, and show a cost benefit. It has to work better, be in left/right limits, and be inexpensive. But sometimes you have to make the investment in new technology. Sometimes you have to make an investment. We just spent 20 years fighting a war that was mostly conducted at the squad and platoon level. In future conflicts dispersal of forces and concentration of fires is key. We fight like submarines not like battleships. We need to incorporate those lessons learned. 
We all know the 6.8x51 cartridges runs hot and has yet to be fully optimized. There is perfection, then there is effective, then there is optimized. Perfection can be the enemy of the great right now. The solutions we seek should emulate current supply chain structures as much as possible. True Velocity’s 6.8 M240 barrel swap effort show this program has technical achievements that WILL bleed over into other programs. True Velocity's effort will reduce the cost of introduction and other barriers of entry for adoption of NGSW technology in other platforms.

Because it is all about this projectile.

The 6.8x51 projectile will be insanely lethal. If you have not seen the ballistics gel testing, I suggest you find it. Then consider what the effect would be on solid organs. The massive cavitation displayed from the videos I’ve seen will regularly create injuries that are impossible to repair in the operating room much less in the field. If you want your enemy to die, you will want to shoot them with this. The technology in this projectile, once perfected, will be incorporated into other calibers. The work of NGSW on projectile technology will make the entire force more lethal.
Ammo case technology took leaps and bounds during NGSW. The Sig Sauer Bi-Metal high pressure case was adopted. By incorporating steel and brass, Sig Sauer was able to achieve pressures rumored into (and beyond) the 80,000 psi range. The polymer case technologies are lacking the ability to sustain similar pressures. But polymer cases are relatively new and we are squeezing everything out of alloy cases that we can. There are several patented (or pending) technologies that address the polymer case pressure issue that are in early stages.  Polymer cases will be developed that can take the pressures of 6.8x51 SIG. But one of NGSW of the greatest impacts will be polymer case technology not only on rifles, but ALL machine guns, indirect fire systems, and aviation. This WILL BE a force wide impact.
I do not have the exact weights of the 6.8x51 from Sig Sauer. But I presume that once polymer cases obtain proper pressures they will be adopted. As a point of reference, the 168 grain 7.62x51 True Velocity ammo is only 7 grams heavier than the 5.56 brass cased M193. This is about .45 pounds per 30 or 3.15 pounds per basic load. I believe that every pound added to a soldier’s weight is critically important. Weight savings will be coming across the entirety of the soldier’s load.  PEO Solider has staff whose entire job is to reduce the soldier’s load.  I also believe that individual equipment will also advance and comprehensive weight reduction efforts will eventually reduce the soldiers load well below current loads.
A common complaint heard online is that the reduction to 20 rounds per magazine or to less magazines. That there is not enough ammunition to conduct the mission. This comment fully disregards the effects of NGSW-FC and IVAS derived technology. Legacy fire suppression techniques rely mostly on volume of fire to achieve fire superiority. This allows for fixing the enemy into place so that they can be out maneuvered and ultimately destroyed. The NGSW-FC and IVAS derived technology will provide an unprecedented level of situational and targeting information. The ability to be much more discriminate with more accurate fires is provided by the network. Volume of fire and maneuver techniques from the NGSW systems is still available. But now suppression while relying on more accurate fire is an option. The most likely outcome being is a far more effective small unit who now has far more accurate and suppressive fires. I suspect that eventually less ammunition over time will be expended.
It begs the question "would you trade 3.5 pounds more weight for better terminal effects, accuracy, and lethality?" The TTP’s will continuously improve, and small unit efficiencies will increase. This was a specific goal sought from the beginning of the program, effective and lethal fire over volume. Accurate suppressing fires over volume suppressing fire depends on the advancements provided by NGSW-FC’s targeting capabilities. These capabilities will proliferate to other systems. Eventually other systems targeting data will be linked to NGSW equipped units. 
Recently it has been postulated that the current war in the Ukraine has invalidated the need for the NGSW systems. That is nothing but an insultingly flippant repudiation of the nearly 8 years of work and preparation by the 10th Special Forces Group and our intelligence community. The only thing the war in the Ukraine has proven is that Foreign Internal Defense conducted by the Special Forces Regiment is extremely effective. That the Theater Security Co-operation Plans are good doctrine. That through Army SF and our IC we can fight extremely effectively by proxy. That our IC's real time intelligence and targeting capabilities coupled with US SF's preparation, training, leadership, honing the Ukrainian will to fight are key ingredients for the defense against a “superior” enemy.
ATGM’s and Russian military malfeasance are also key factors in the current state of affairs. But Ukrainian success has come at very high cost. Many of the major cities and infrastructure have been damaged or destroyed. About 15-20% of the Ukraine is still under Russian control. While sources and exact number vary, tens of thousands of soldiers have died on both sides. Very brutal fighting is yet to come in the east and south. Americans should not and would not be willing to accept the costs the Ukrainians have had to pay to achieve these “victories”. Additionally, the Chinese are not the Russians. Plus, this war is far from over in the Ukraine, we should hold our opinions on NGSW invalidation until it is actually over and the true costs are known. With the losses I suspect are coming, it will probably validate NGSW's force protection/situation awareness elements.
I have ALWAYS held the opinion the answer we seek is a 2-cartridge solution. The same tech applied to the 7.62 case will be applied to the 5.56 case as the technology is perfected. Eventually this technology will expand into the M4 and other existing systems. Which means the two-case solution we have fielded as an army for decades will stay. While I understand the need for the fully powered heavy infantry as imagined by some, real world doctrine will eventually also push for a much more lethal M4. The NSGW systems are far too expensive for all combatants, even in a full mobilization scenario. While Sig Sauer and some military leaders are surely pushing for 100,000 total platforms. Eventually reality will prevail over profit margins and a lower number of XM5’s will be fielded, but I suspect the full number of XM250’s. I consider the XM250 the prize of this program. The XM250 has an opportunity to replace a large number of belt feds in the inventory.  I expect tech bleed over into the M4 will sustain that program as many units, to include SOF and scouts, will find a much more lethal NGSW tech M4 more suited to their mission. The XM5 and XM250 will supplement the capabilities of an enhanced M4 in these units.  
I believe the NGSW systems are early in their development. The ammunition and firearms are not yet optimized. The TTP’s that NGSW-FC and IVAS derived technology will enable are just now being discovered. The soldiers load reduction is a focus of the army. Even if the gun might be marginally heavier, eventually the total load will be lighter. The M4/M16 has nearly 60 years of development, and people like me are just getting going on the XM5 and XM250. We still have a long way to go.