The iron sights on the Owen Machine Carbine and the F1 Sub Machine Gun are mounted on the right hand side because they cannot be effectively mounted on the top.

Both weapons have top mounted magazines which would block the sightline of a top mounted sight. The weapons are not designed to accommodate left handers. When fired from the shoulder the weapons are placed firmly against the right shoulder and with the right cheek against the top of the butt the eye naturally sights past the right of the magazine.

When firing instinctively from the hip the iron sights are not used but the top of the magazine in the lower part of the shooter's field of vision is used to improve awareness of the weapon's alignment.