My son had never shot an M-16, but managed to qualify as expert at USMC boot camp despite having rifle training cut short by bad weather. He got 5 in the black at 500 meters with iron sights.
I used to take the kids shooting out in the country. Mostly .22s but I did let them shoot an AK clone (MAK-90) or my SKS often. Ammo for that was so cheap way back when.
Must have been heavy rain washing the 'pasters' off the previous bullet holes on the target.
I had a very good score on 'pre-qual day' and was hoping for bad weather on Qual Day. If so, my pre-qual score would have gone into the record.
Sure enough, Qual day arrived with a snowstorm at Parris Island. We were blowing 1" diameter snowflakes off of our rear sights. But, our scores counted because the 'pasters' were still sticking to the targets!
Overall, it was probably a good thing. If my pre-qual scores had counted then I'd probably ended up a sniper in Vietnam. No telling where that would have led.