Very few people are capable of any real accuracy from open sights past 200 yards. Getting that proficient takes a lot of practice which the hunters of old had. The sights themselves are just as good as they once were, but it is the shooters and shooting habits that have changed.

I have a Whitworth Express in 375 H&H that came with the 3 leaf model. I've played with it but I learned really quick that anything over 150 yards was pretty safe for me. Frankly a peep sight is the way to go if you take off the scope. Peeps are good out to 300 yards since your eye doesn't have to try and focus on 3 things at once. That is why the military went to them.