M1A National Match Rear Aperture Some Assistance Required

[Travis Bickle]

I picked up an M14 with a National Match rear sight assembly.
Has the hooded rear aperture that can be rotated 180 degrees (clockwise or counterclockwise) to adjust 1/2 MOA to fine tune POI vice the standard 1 MOA on the actual elevation knob.

I have been trying to get this to make sense in my mind; if you rotate the hood 180 degrees it will adjust the POI 1/2MOA.
So does that mean if I keep rotating the rear aperture in a certain direction, will it keep adjusting POI by 1/2 MOA increments?
Should it "bottom out" if I keep rotating it so I know how many clicks it would take to put it back at mechanical zero like a rifle scope turret?

I am trying to mechanically zero the front and rear sights so I can go sight her in at the range. I am not familiar with the NM sights but I am very versed in the standard M14 platform.
Anyone with actual experience with a NM rear sight out there that can explain this device to me?

 

[machman]

It is an "on/off" adjustment.

 

[Odd Shot]

Rotating the peep 180 degrees shifts the POI a half MOA up/down. It doesn't continue to shift it further up or down with more rotation. It's just a "back and forth" kinda thing

 

[Travis Bickle]

Rotating the peep 180 degrees shifts the POI a half MOA up/down. It doesn't continue to shift it further up or down with more rotation. It's just a "back and forth" kinda thing

Ack.
Click once clockwise would then be 1/2 MOA up regardless of rotations.
And click once counterclockwise would then be back down 1/2 MOA regardless of rotations.

Makes sense. Thanks all!