No biggie, I can hit a 1sqft target at 1000m using open sights on my M1 Garand (learned to do it when I was in the Navy). Just have to know the ballistics of your round, how to judge and adjust for windage and elevation, and have a steady firing posture, and a decently accurate weapon.
Scopes are nice, but you shouldn't rely on them all of the time.
a 1 ft square target at 1000 yards? You can see that? (lol). I have trouble seeing the 5
foot black dot at 1000 yards, as it is 3/4 the width of the front site blade at said yardage.
Neat thing is, the center of a fuzzy target is still the center.
Glass is not really for improvement of basic ability to hold steady and squeeze a round, but they sure do help see what you are aiming at!