Originally Posted By backbencher:
"It can work if its forward but its faster if the rear sight is close to your eye. That way all you have to do is put the front sight on the target. I find an apature sight up that far to be very slow to use."
Which is odd, b/c all of the early 20th century battle rifles, save the Enfield, started out w/ mid mounted sights, the theory being a rear-mounted aperture sight would be too slow, albeit has more inherent accuracy due to the longer sight radius.
I believe that was because in the early 20th century most of the rear apature sights were very small for maximum precision at long range and such as set up is not fast. Open up the apature a bit and you get a really fast and dirty sight for close in. (AKA Ghost ring)