I must admit a 3 shot semi auto grenade launcher underslung...

I must admit a 3 shot semi auto grenade launcher underslung under a rifle would be pretty bloody useful.. (although holding all those rounds in the chamber could get heavy, but soldiers are tough)

And as robotic systems become more and more prevalent an electronic ignition system seems like the only workable solution also, especially considering the machines can't fix the weapon if it jams so mechanical parts are doubly out

It's just all the other stuff keeping me out of this share