Aw, c'mon guys, you're being too modest!

A cigarette-box at a hundered yards hunkered down over a steady rest?
Check page 49 of the 1910 H&H catalogue, they put 8 out of 10 into 2 5/8 x 2 inches with an open-sighted DR in front of the editor of The Field. Ten out of ten went into 3 1/4 x 3 3/8 inch.
In fact, check the H&H Trials for the 12-bore Paradox: the tester put 10 out of 10 into 5 3/4 x 3 3/4 inches in 1886! A Paradox!

We now have better bullets and better powder by far!
...but perhaps not better marksmen?

BTW, this is starting to look like a disagreement: it is not! A scoped medium-bore is definitely the best for plains game including croc for the vast majority of hunters today. But this doesn't mean an express-sighted double wouldn't work! Before decent scopes appeared, most folks did just fine with their open-sighted DRs. ...for everything! ...for decades!