Alternative to 6.5 Grendel?

[Trooper]

Every time a new cartridge hits the market or a new platform is deveoped most are not really all that new and usually not significantly improved, least we forget the entire concept of an assult rifle is that engagements do not typically exceed 400 meters so having a cartridge effective at longer distance is not needed the Russians take th concept one further by only requiring the rifle to hit a man sized target at that distance putting 10 rounds up a gnats ass at a 1/4 of a mile is an impressive feat but it isn't required in the typical combat enguagement

So nothing will change, the only innovation I could see happening that would succeed in revolutionizing the assult rifle would be the development of caseless ammunition which would allow everything to become smaller lighter and in theory simpler as there is no need to extract caseless ammunition, but such projects have been shelved in favor of more conventional designs as there has not been the need for more advanced weapons, but you never no what need the future will bring

Though according to the internet so it must be true the US is working on developing the caseless concept for the role of LMG...

We are doing similar procedures with the use of the Designated Marksmen. The problem is that we have two rifles, two cartridges and lots of spare parts. Likewise two MGs (M249 SAW and M240 GMG). If we can have one cartridge do both the mission of the 5.56x45 and 7.62x51 that saves a lot of logistics. Plus the 5.56x45 has been shown to not be effective against stone or brick buildings (same with the Russian 5.45x39).