Question for firearm enthusiasts, visionaries, SciFi fans

So my wife has a co-worker that is writing a book that takes place roughly around 2150. He's aware I'm a big SciFi fan, firearm enthusiast, and a bit of a historian. He asked me if I could envision what a firearm might look like at that time, and what kind of advances in technology we might have made that would transfer to firearms. I have to admit, I was a tad at a loss because looking that far ahead gets awfully blurry. While technology has made many fields go leaps and bounds from where they were 100 to 200 years ago, the firearm has basically remained the same. A controlled explosion to propel a projectile. Feeding has changed, ammunition has changed, but the concept is largely the same and there haven't been many major breakthroughs.

I suspect that will most certainly change, but to what degree, and how quickly? When people think future guns, most minds go to energy based weapons, like "ray" guns, lasers, plasma. While I have no doubt you will see vehicles armed with such weapons (as to some degree you do now), I think the energy requirements, even that far off might not be something that's possible, outside of a something akin to what a squad armed machine gun equates to now. One guy armed with something capable of more firepower, but issuing that out to every soldier just wouldn't make sense. Granted much of that isn't in regards to cost (although that's certainly a factor), but also load. However, exoskeletons capable of making soldiers carry more weight, and reduced weight of ammo based off of energy as opposed to what we currently have would also reduce loads.

I think stronger materials will be a factor. I also think caseless ammo will certainly be a thing allowing for greater velocities with more powerful propellants, less weight, and less potential malfunctions. I think electronics will also factor hugely into firearms, with some form of AI capable of giving you info on ammo count, and doing instant calculations on distance, Coriolis effect, windage, temperature, all factors on where a projectile is going to go. Hell we're already working on self guiding ammo that micro stabilizing fins will help guide to the target much like "smart" bombs do now via GPS. I also think much of the mechanics in a firearm right now will be replaced by electronics, like a firing pin for instance. No need to have and move a pin repeatedly when you can just hit the propellant with an electric charge and off it goes. This would also allow for greater fire rates.

Optics would have changed dramatically by then as well. Mind you we will probably always have the post iron sights for when we might need them, but optics will have reduced in size and be much more powerful that far into the future, much of the info being fed right to the user via some form of HUD. So at this point what I'm envisioning is something roughly the size of a P90, perhaps firing ammo roughly the size of a 5.7×28mm but capable of twice the range and kinetic energy of a what is currently possible, containing at a minimum of 50 rounds, with AI and optics assist allowing for shooting from behind cover and being extremely, perhaps even pin point accurate.

Please share your thoughts. I'm very interested to know where folks think the future of small arms is going.