Just to be clear, I am an advocate of getting close, for several reasons, one being the sport of things. If you are in a situation where you might expect to have to make a 400 yard shot in a bad situation, like on a sheep hunt or Africa, then you would be carrying a higher powered scope and a higher powered rifle. But with the coyote problem we have, I will (and have ) shot them at 400 yards and more. I have a different set of ethics for these vermin, but so far have never needed more than one shot.
These older scopes were simple 2.5x, 4x and 6x, and they had rather fine reticles. Hunters used them like super iron sights. Just look at all the sniper scopes of WWII: mostly 2.5x Lyman to 6x Zeiss Marburg. Even well into the 1980s, the 4x ranging scope and 6x42 still ruled.
I am a big lover of iron sights, open and receiver sights, and of unencumbering the rifle from large scopes; ten of my .308s wear them, and eight of those have nothing but irons. Next step for the 7x64 I am building is a top front sight.