EmericD said:

The training / practice 6.8x51 mm does not seem to deliver something the 6.5 mm Creedmoor is not already doing, the GP & SP loads are still in the development phase and there is no "match" ammo planned.

The 6.8x51 ammo situation seems insufficient reason to resume the 6.5 CM program. 

They also need to develop GP/Ball, SP/AP and Tracer ammo for 6.5 CM machine guns.

It would be much easier to develop 6.8 match ammo and let the Army do the others.

EmericD said:

Special Forces shoot  a lot of ammo and they need to replace their weapons every ~5 years, so they could adopt 6.5 mm weapons now and wait until 2027-2028 in order to switch to the 6.8 mm if the cartridge is still there.

That sounds logical.  Assuming the 6.5 CM weapons are fully developed and ready for production.

SOCOM can use ordinary FMJ ammo in the 6.5 machine guns while EPR ammo is being developed.

Considering that we are just now adding a 6.5CM to our SF arsenal, something that i have been heavily involved in. Its about getting guns now not 10years down the line when 6.8NGSW might mature to wholesale adoption .Aslo with 6.5CM you can these days choose from bunch of gun and ammo manufacturers, getting something adopted that only SigSauer makes is a big no no.

While true SF uses their guns a lot it's still hard to budge the bureaucracy to purchase something new. For example, buying a replacement barrel ,upper or whole gun of same model is no big deal but adding something new is a very slow process. The 6.5CM we are now introducing are sort of an experiment coupled with Steiner IFS scopes with ballistic computers and .300NM, 338NM bolt action guns to see what gives , before Military even remotely considers any wider adoption.

Mr. T (MrT4) said:

Considering that we are just now adding a 6.5CM to our SF arsenal, something that i have been heavily involved in.

To which "we" are you referring?

EmericD said:

I'm not really convinced that the FCS will really help to hit a moving target at 600 m.

That's okay.  I'm not convinced that the FCS will really help hit most targets -- moving or stationary -- at any distance in combat.

EmericD said:

But against a visible, static target (something very rare on the battlefield), the FCS will be a huge game-changer.

Which means the FCS will not be a game-changer.  So, does it really matter what caliber the next-gen infantry rifle is?

Weapon or caliber is of minor importance , optronics are absolute gamechangers

FCS will help in many situations , even with moving targets as an individual soldier will be able to accurately set his dope on the fly , for example range a structure in the area and when fleeting targets appear have much higher hit probabilty. 

FCS will progress to electronic triggers and then your dumb poorly trained grunt will have near sniper-like capability. Any new firearm developed without provision for an electronic trigger is borderline obsolete before it hits the market.

Drones are the obvious target and an easy one due to lack of ground clutter, but FCS will develop to handle ground cutter noise better.

https://www.youtube.com/watch?v=Zvhrhw4jIC4

https://www.youtube.com/watch?v=91sf7B6WpbI

Mr. T (MrT4) said:

Weapon or caliber is of minor importance , optronics are absolute gamechangers FCS will help in many situations , even with moving targets as an individual soldier will be able to accurately set his dope on the fly , for example range a structure in the area and when fleeting targets appear have much higher hit probabilty.

Citing a single scenario wherein the FCS would probably help is hardly proof that it is an "absolute gamechanger" for infantry combat.  I can cite many examples of scenarios wherein the FCS would be unlikely to help.

Mr. T (MrT4) said:

FCS will progress to electronic triggers and then your dumb poorly trained grunt will have near sniper-like capability. Any new firearm developed without provision for an electronic trigger is borderline obsolete before it hits the market.

Perhaps, but I was discussing the NGSW-FCS, not possible future systems.  

Mr. T (MrT4) said:

Drones are the obvious target and an easy one due to lack of ground clutter, but FCS will develop to handle ground cutter noise better.

The primary target of the XM5 rifle is enemy infantry, not aerial drones.  After watching videos of infantry fights in Ukraine, I'm skeptical that the XM157 FCS would make any difference in most combat situations. 

IMO, hit probability on the battlefield -- in contrast to the firing range, where targets are clearly visible (as shown in the videos you linked) -- is limited much more by the use of bullet-firing weapons, than the sights.

I'm thinking perhaps the OICW program actually had a sound basic concept for a truly game-changing weapon system, but just botched its execution.

stancrist said:

Which means the FCS will not be a game-changer. So, does it really matter what caliber the next-gen infantry rifle is?

That's not exactly what I meant.

The experience we have with the FELIN system is that most of the system capability is useless 95% of the time, so issuing a FCS to every and all soldiers is both expensive and ineffective.

But, having at least one FCS per combat team is an interesting option, because from time to time you have opportunities to prepare your fire, so having one or 2 guys with that capability is a real boost, but that's the reason for Designated Marksmen.

My conclusion is that FCS are great, but one for the DMR and one for the AR is probably enough.

There are better choice than FCS for the rest of the team.

stancrist said:

I'm thinking perhaps the OICW program actually had a sound basic concept for a truly game-changing weapon system, but just botched its execution.

The firing sequence of the OICW needed around 12 seconds, other similar programs needed similar timeframe.

Imagine having to stay on the battlefield, in the open, without moving, for 12 seconds in order to be able to shoot...

Now, add the fact that even a ~1 lbs defensive handgrenade needs to explode at less than 5-7 m of it's intended target to be effective (and sometimes much closer), and then try to launch such grenade with a sufficient muzzle velocity so it could reach it's target in less than 6 seconds...

A Milkor MGL and a PDW are probably as good as any OICW, and even this combination is not widely used.

EmericD said:

My conclusion is that FCS are great, but one for the DMR and one for the AR is probably enough. There are better choice than FCS for the rest of the team.

I agree.  That approach seems more sensible to me than FCS for everyone in the squad.

But, I'm also wondering if it might now be possible to field a successor to the assault rifle.

Rifle bullets just seem so inferior to bursting munitions for most infantry combat scenarios.

EmericD said:

       stancrist said:  I'm thinking perhaps the OICW program actually had a sound basic concept for a truly game-changing weapon system, but just botched its execution.

The firing sequence of the OICW needed around 12 seconds, other similar programs needed similar timeframe.

Imagine having to stay on the battlefield, in the open, without moving, for 12 seconds in order to be able to shoot...

That is certainly undesirable.  I did not know that the OICW firing sequence took so long.  Surely that problem can be solved?

EmericD said:

Now, add the fact that even a ~1 lbs defensive handgrenade needs to explode at less than 5-7 m of it's intended target to be effective (and sometimes much closer), and then try to launch such grenade with a sufficient muzzle velocity so it could reach it's target in less than 6 seconds...

ToF ~3 seconds in this example:  https://youtu.be/161JT0WRVf4?t=355

stancrist said:

Rifle bullets just seem so inferior to bursting munitions for most infantry combat scenarios.

Then, maybe, we can design a high explosive round that could be fitted around the barrel of the rifle, launched with  ball ammo, without having to close the rifle gas port, so you could immediatly fire "kinetic rounds" after launching the HE round?