Nah it's not for NGSW, its for the US SOF and their attempts to replace 5.56 and 7.62 with a more accurate round. Unlike 6.8 Kickback 6.5 LICC (that name will never not be funny, thanks FN) is driven around being able to be easily reconfigured into 5.56 for ppl who don't need the extra punch.
As for why the US has been chasing all these rounds, its "Overmatch" based upon very
*very* unwise decisions in Afghanistan. To quote the Army at the start of the 6.5 --> 6.8 change:
"The Next Generation Squad Weapons Team structured an innovative selection and contracting approach to identify and deliver technologically advanced small arms and ammunition that provide overmatch against peer and near peer threats."
[US Army Rifle Program History]
Concurrently to the NGSW push there is the
which was also about Overmatch(tm) sorry for the powerpoint- its rough, but the general timeline of things goes like this:
In the 1990s, the US Army was looking new rifles. This gets us the XM29 OCIW and later XM8. The Army does not think it really important to try and rush them out, as we have (two) future solider programs on going. the XM29 will make it to 2001 before being split into the dedicated rifle and AB grenade launcher (XM25)
In 2004, the US Army starts the Lightweight Small Arms Technologies- which *is not* designed to make a rifle, only a new machine gun.
Similarly, the XM8 is going through trials at this point. The 40mm GL is liked, the rifle is okay. However, the Army is entering its COIN phase so the rifle is not likely to be adopted even if it trials well.
The LSAT and XM8 continue to roll in limbo, until 2008. XM8 is dropped as the US Army doesn't want to *pay* for the thing, and the LSAT Machine Gun is entering very limited ideas with its caseless and polymer ammo. In 2010, Textron (having bought AAI) have to change the caseless ammo as it's based on the G11's patent and is not healthy for the environment. By 2012 they have built several LMGs and two rifles.
The Army, tests the Machine Guns and they love them. Troops enjoy having a MG that weighs about the same as a rifle with all its attachments and 150 rounds of 5.56 caseless. Both Caseless and CT rounds perform well even hitting things like "cook off times being on par with cased ammo" (They achieve this by being modern and also because we have good plastics but shh) The only issue the Army sees is!
"Why do we need this rifle, we're going to be leaving Afghanistan by 2014 at the latest." So, LSAT is rolled into the NGSW program.
NGSW starts out as just "make 5.56 do the job of 7.62 but in a way that isn't too ground breaking." Which is where the 6.5/6.8 debate comes from. US SOF want their own super round and start the LICP (later LICC) program.
We jump to 2016, as both the LICC and NGSW programs have picked a solution. US SOF want 6.5, US Army wants 7.62- so they will take 6.8x51mm because they decide making the rifles hit further. From that decision we end up with the SIG rifle and for the US SOF the FN IWS.
FN's idea was to make a round that could be both poly or brass because US SOF did not care about weight.
SIG's round is brass-steel hybrid because all they had to do was be "lighter than 7.62x51" which they did!* [end]
*rules lawyering is how they also win the pistol contract btw
I have followed these programs for way to long, because I've always argued for upgrades to the M16, updates to 5.56 or just biting the bullet and eating the costs of caseless ammo. Instead the US Army wishes to fight the last war, because learning from it would take answering some painful questions- and don't get me started on whatever the hell the USAF's upto.