I'm an engineer by training. . .
. . . which is why I like talking this stuff so much.
In the mid-future, say 30 years would be my guess, there is a good chance your firearm/optic will have a THz frequency scanner or doppler radar system integrated, that tracks your rounds, and computes the correction for follow up shots.
The THz scanner would also let you know who is packing in the area; concealed carry won't be concealed anymore. (Think of the scanner as akin to the x-ray machine in Total Recall. That's about how it works.)
I expect all but the cheapest optics to go digital by that time as well. The state of the art of computerized optics is just too good for pure "dumb" optics to compete on the high end. That, coupled with newer battery tech (Lithium air, which I mentioned above) will mean the optics will likely have multiple year run times. (and be smart enough to go into hibernation when not in use.)
We're also likely to see exotic materials cladding the barrels, both on the outside and inside. You can already get a Carbon Fibre reinforced barrel on Volquartsen 10-22s (and others) but as the technology gets cheaper the uptake of such composite barrels will be much more common. I could see a traditional thin steel barrel, with carbon fibre, nanotubes, or graphene on the exterior for stiffness and strength, and a very thin layer of a very strong, low friction ceramic inside the barrel, with laser cut rifling that goes into the steel.
These advances are all in testing now (well not the THz scanner integration) but the technology is nowhere near robust enough for actual use yet. (exception being the carbon fibre reinforced barrels.)