Close-up of BSA breech
This view shows off the lateral adjustment of the rear sight of a BSA Martini-International MKII. This is a single shot .22 rimfire target rifle capable of good accuracy. Also visible are the breech block in the dropped (open) position and the extractor / ejector claw at the foot of the loading ramp. These guns are easy to operate quickly and are good for timed fire shoots. Note the vernier adjustment for the sight, this also means that they can be quickly returned to zero after using them at a different range. The sights used for .22 shooting are almost always aperture sights i.e. you use them by looking through a hole in the rear and front sight with the aiming mark on the target in the centre of the hole in the foresight. This method is very accurate for target shooting, but useless for hunting, as it restrict the field of view too much. By way of comparison look at the Anschutz breech.
