While we're still sticking to a basic AK with rails etc,Russians seems to be trying out something new (?) with their upcoming AK prototypes
Meet AK-521
This time with SG550 series inspired (i believe) two-section receiver that hinges at front and machined top receiver with picatiny rails on top, a spring loaded dust cover on its charging handle slot that automatically opens and covers the slot when rifle is cycling.Lower receiver seems typical AK74 style stamped sheet metal one with modifications to make it work with this new upper etc.
Also the fire selector is shortened from typical AK style selector as no longer it doubles as dust cover for charging handle slot when on safe.
Article written by a friend of mine from where i took the pictures (i.e. Source) =
On Saturday, images of a new Kalashnikov-iteration in-development rifle emerged on social media, named the “AK-521”. Intriguingly combining the characteristics of its “competitor” rifle, this new Kalashnikov product might end the debate here once and for all.
frontiervedette.com