A2 sight question-SIMPLE

[Mauser lover]

Simple question. When you change apertures on an A2 style sight, is the windage knob supposed to move?

Thanks.

The story: I bought some VERY cheap sights that look like they are supposed to be essentially A2 style, just not in a carry handle (they are backups). When I switch from the long range to short range aperture (and back) the windage knob moves about a quarter turn. It moves back when I change the aperture back, so I’m wondering if this is a feature or a bug.

I’ve never had a real A2 sight, so thank you to those of you with experience.

 

[NIGHTLORD40K]

No, the knob shouldn't turn- you probably have a weak detent.

Now, the aperture WILL move a tiny bit left/right on the screw when you flip it, but not enough to make any noticeable difference in POI.

 

[C-grunt]

No it's not. The detent is either weak, broken, or mis-installed.

 

[Mauser lover]

Well… that stinks. It’s brand new. It doesn’t feel really stiff, so I’m going with a really weak spring. It does click for adjustment, but it’s not really positive.

 

[R Reed]

Unfortunately brand new means very little when you buy "very cheap". It should definitely not be moving past the detent when switching apertures.

 

[lysanderxiii]

No, the knob shouldn't turn- you probably have a weak detent.

Now, the aperture WILL move a tiny bit left/right on the screw when you flip it, but not enough to make any noticeable difference in POI.

Actually, it would make a difference - about one click. But, the aperture holes in the "L" are offset to compensate for the left-right movement due to the thread pitch.

 

[NIGHTLORD40K]

Actually, it would make a difference - about one click. But, the aperture holes in the "L" are offset to compensate for the left-right movement due to the thread pitch.

Huh, makes sense. First time Ive actually heard that though.
Great....now I gotta bust out my micrometers and measure all my sight apertures!

 

[Varminterror]

I’d pull it apart and make sure the detent is moving freely so the spring can do its job and that the detent notches are deep enough to really grab. Cheap is one thing, but it isn’t such a complex device - a little cleaning or deburring might fix it up. Or chasing the threads through the sight, if it is too tight on the screw that it overcomes the detent.

 

[Mauser lover]

I can feel all the notches, maybe they aren’t as deep as they should be, but I do feel them. The spring is REALLY weak. So, it might be broken, or it could just have been a VERY cheap spring to start with (surprise!) that has lost its springiness. When I get a minute I’ll punch out that pin and see, but I’m guessing I need a spring.

Thanks for the helps, peeps!

 

[lysanderxiii]

Huh, makes sense. First time Ive actually heard that though.
Great....now I gotta bust out my micrometers and measure all my sight apertures!

The two apertures are offset 0.007", about one click on the A1 and two clicks on the A2.