Vox has a sort of video from DOD of a test of a bullet able to change course in mid-flight. (Don't ask me how they did it.) The bottom line to me: add "sniper" to the list of jobs endangered by technological obsolescence. With such a bullet even I could be a sniper.
In basic training you spend a bit of time on the rifle range. Although I'd shot a 22 rifle to kill skunks and possums on the farm, I was far from being a marksman. That was very evident in my early sessions on the range. When my company went to the range for qualification tests, I was seriously concerned about flunking, which would have meant having to repeat some weeks of basic. As it turned out, the test with popup targets (I don't remember that we'd trained on them, definitely not in the way the test went) was such that I passed, almost rating as "expert". The key was that I didn't have time to get nervous, so I could react to each new target and fire without over-thinking.