When I went through Army basic training at Fort Leonard Wood, Missouri back in 1961, the M14 was being issued to the field troops, but there weren't enough of them to go around, and all the basic trainees (Boots to you Navy and Marine guys) were issued well worn M1 Garands.
The "Trainfire" concept of popup targets out to 600 meters (may have still been yards then, I don't remember) that dropped when you hit them or the specific time limit had passed was in place and believe me, the 600 meter target was NOT difficult to hit at all if you paid attention to your sight picture & bullet drop during the practice sessions. We never got the chance to shoot at ranges beyond 600 at Leonard Wood, so I never got the chance to shoot any farther than that with the M1. The 30-06 round was (and is) capable of doing lethal damage quite a bit farther out than that.
My father tells of hitting and sinking 55 gallon steel drums at sea out to 1000 yards or more off the fantail of their ship with a 1903 Springfield while they were on their way out to the South Pacific during WW-2. His eyes were quite a bit better than 20-20 though, and even at 97, they are still much better than mine. He's color blind, and I suspect the enhanced contrast he experienced from not being fooled by shifting color patterns of the waves had a lot to do with being able to see those barrels out that far. He certainly was never fooled by the camouflage in use at the time and almost got in trouble once from spotting a camo'd installation that they weren't supposed to be able to see.