Flavor of the world is supposed to be limited resources (voted in another thread).
You can propose that we can have changeable barrels. It would serve the purpose you want .
But it was not mentioned anywhere here, so we can assume for now that we have at least enough to have two types of assault rifles.
Changeable barrels would make it more versatile, but would still be more resource intensive and would keep the untested 6.8 round meant for closer combat. I would like us to be able to add things to the barrel, such as an under barrel grenade launcher, in the future.
B) No redesigning old technologies in general. We have no army, we don't need to reform ourself to adapt to high tech weapons. No need to reinvent howitzers or stuff like that
We have an army, it is the largest part of our current military
. We do need to reinvent old weapons, simply because we are so far behind. Besides, this is 6 years into the future, we would still be using exactly what we have now.
C) No spending our effort on something that will improve effectiveness of our army by few fractions of percent (like handguns). If you want a small portable sidearm, try new approaches that can spillover to other areas
Handguns can spill over into other areas. Pilots, navy troops, and drivers all need a small weapon that they can use in cramped spaces. Besides, they are cheap and easy to make. It isn't like making thousands of M1911s would be as hard as making a single battleship.
And in case you missed the last minute edit:
This should lessen the barrel climb substantially while still keeping the action simple and reliable.
The long action is more reliable, we should stick with it. Most people would agree it isn't a *huge* deal anyway, so there is really no reason to change the design from what has worked.
And I did get some votes for the current design:
. Standard 5.56mm Kalashnikov rifle. Stirk, tryrar, GUNINANRUNIN
-1.1. Bullpup 6.8mm Rifle. Taricus, Akkudakku
-1.2 Accessory Kit for rifle. Khaiel, Taricus
-1.3 Short-stroke gas piston, striker fired. Akkudakku
2. Standardised sidearm.
3. Man-portable Mortar. Akkudakku
4. Badger Tank. Taricus