So how is a Lyman 57 or Redfield 70 or Lyman 30 1/2 without a screw in aperture any different from an M1 Garand or M1 carbine sight?

I've shot them all extensively. I can clearly see the outline of the back sight hole on all of them. None of them qualifies as a ghost ring sight by my definition.

You look through the hole and your eye instinctively centers the front sight.

The size of the hole may be different, I but see absolutely no difference in the method or results.

I think we are splitting hairs on the language.

"You cannot invade mainland America. There would be a rifle behind every blade of grass"
~Admiral Yamamoto~

When the people fear their government, there is tyranny; when the government fears the people, there is liberty. ~Thomas Jefferson~