Red dot / parallax

[Ad Astra]

Recently put a reasonably good red dot on a 22, a Vortex Crossfire.

When I sighted in, was chasing the zero around. A bit frustrating. With the gun unmoving - in a lead sled, the dot seemed to be moving off-bull when I address it. Up-down, left-right.

Yet it's a parallax-free optic. Finally figured out they all do that at shorter ranges, seemingly. Hold the dot on the horizon and the effect is lessened or gone. Yet I'm not shooting this one at 600 yards. No wonder I prefer low-power scopes. Something tells me I won't be able to shoot this accurately at shorter ranges. (Would an EOTech do the same? I suspect so).

Anyone have any hints, clues or insights to living with parallax or the illusion thereof? It's a slippery topic.

Thanks.


AA

 

[nortac]

While a red dot is allegedly parallax free, you will have more consistent accuracy if you keep it centered in the field of view. My Burris FastFire III has a single vertical reference line on the lower portion of the sight body below the "window" and the Vortex has a double line reference mark on it.

 

[nortac]

An expansion on the above explanation, if the dot isn't centered each time you pull the trigger, then your grip and alignment of pistol, wrist, shoulder and eye are not the same, potentially inducing error. So it may not be that the dot not being centered, in and of itself, directly causes an error, but it is an indication that other things are misaligned and that does cause a sighting error.

 

[Ad Astra]

It's appreciated. My eyes may be a factor, too. Astigmatism or something.

Luckily I didn't buy a high end one - but doubting it's the Vortex.


AA

 

[nortac]

I don't think that spending more for a higher end RDS would improve your situation. I had installed a Trijicon RMS on my Glock 19. I ended up taking it off and going back to iron sights. The Glock grip angle is such that my sights don't naturally align, YMMV. With iron sights, that misalignment is readily corrected quickly, but with the red dot sight, I spent forever trying to align the dot. I sometimes compete with my Glock 19 and most of the time it is my "truck gun". I need to be able to align my sights quickly in either case!

 

[Borderboss]

If the gun is locked down in a shooting vice and the dot moves without you touching the gun, there's something wrong with the optic. I've been shooting red dots for 30+ years and have never had one do that. Either the sight is loose on the base or something is loose within the sight.

There really is no parallax with a red dot as there's no magnification. An astigmatism won't make the dot move around but it will make the dot look like it's not round. I have that issue. But still, the dot doesn't move when the gun is untouched.