benEzra, I was confused about the settings, I wasn't sure if it was read of the middle of the slider or the front. It is set for 100 yards, but 6" high at 50 seems dramatic to me.
That is quite high. Assuming the same sight height for your rifle as for a regular AK (2 inches above the bore), my ballistics program says your rifle should be only 1/10" high (not even measurable) at 50 yards. So if you are shooting 6 inches high at 50, you are way high at 100 and are probably zeroed around 400 (guessing).
Definitely get the little tool from the buttstock cleaning kit (thanks, Nalioth!) and screw your front sight pin OUT (up, more threads showing) until you are more or less zeroed at 50. Then back up to 100 and check zero, it should be close.
(Screwing the front sight pin UP pushes the muzzle DOWN relative to the line of sight, and hence moves the point of impact down.)
One note when zeroing an AK, though--when shooting from a bench, I've had best results with the rifle supported by something fairly soft. A rolled up coat under the handguard (not the barrel, or else you'll have powder stains on the coat) atom a hard rest, or even shooting without a rest with my left elbow propped on the bench, etc., rather than the barrel or handguard resting directly on a hard rest or firm sandbag. The vibrations caused by the heavy gas piston getting blasted off the cantilevered gas block can cause the rifle to jump off a hard rest and shoot a little high (though probably not 6 inches high at 50 yards). Or, if you are shooting from a rest, put the rest as far back as possible, i.e. under the front of the receiver just ahead of the magazine and not under the barrel or handguard). I've gotten more consistent groups that way. And make sure you grasp the forend fairly firmly, so that the rifle is zeroed the same way you'd be shooting in the field.
