truth of the matter is how good are your eyes..
and, the closer to the barrel the sight the morre suited for closer shooting, e.g. a barrel mounted lazer on the tip is like 2 yards to 20 yards, dot on the head and hey presto, doesnt matter if its at the side eather, as long as its not too far out..near as poss.
open sights with good eyes..30-40 yards easy with them HW lollpop n back V.. exselent. but, near too deadly. as is the 4x20 scope out to 40 yards if you can get the velosity without going over the limit.. again the 4x20 is a good ratter..its low on the barrel, good near to.