Red dot optic issues

422 Views 15 Replies 7 Participants Last post by Zahnarzt, 4 mo ago

Zahnarzt

Discussion Starter · 4 mo ago

Is it common to need to re-sight in red dot optics often?

On a recent range trip, I noticed the red dot sights on 3 of my pistols were not zeroed, whereas they had been fine the last time these 3 were fired at the range maybe a month ago. The first is a Holosun 507K on an Sig P365XL. The second is a Vortex Venom on a Walther Q5 SF. And the third is a Vortex Venom on an HK VP9L.

All 3 have the optics mounted on the slide. I haven’t noticed any issues with the mounting screws loosening. None of them were dropped.

They all seem to have a consistent issue. Point of impact is lower than point of aim, by a significant amount.

At first I thought maybe I was just having a bad day with accuracy and my trigger control was haphazard. But my wife who is a decent shooter had the same issue to about the same degree. So there’s a chance we were both having a bad day with accuracy, but I really doubt it.

What’s also strange is as I attempt to re-sight in the optics, I reach the limit of the optic in how far I can adjust.

Any thoughts/help is much appreciated.

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oldnrusty38

· #2 · 4 mo ago

It is uncommon for an optic to need re-zeroing unless you have removed the optic from the firearm or have switched to a different ammunition.

How much of a shift are you having?

Initial trouble shooting questions would be what has changed simultaneously across all three pistols? Ammunition? Were all three optics removed and reinstalled for maintenance? Any sort of electromagnetic interference?

Very strange for three optics on three different pistols of different manufacture to all be shooting low.

My first thought is either a shooter or ammunition problem.

Perhaps someone else can chime in with a bit more knowledge but this is a strange one to be sure.

Reactions: 1

Rich J

· #3 · 4 mo ago

Hmmm. No, not common.

Do you have a torque stripe on the optic mounting screws? Have you retorqued the screws?

Are you shooting the same ammo?

Replace batteries lately?

Running out of MOA travel is a big deal. Can you describe your zero process?

dldarrow

· #4 · 4 mo ago

What distance are you shooting and noticing the low point of impact? You will have a mechanical offset because the optic is mounted above the muzzle. The closer you are shooting the more pronounced the difference will be.

Zahnarzt

Discussion Starter · #5 · 4 mo ago

Shooting at 7-10yds.
I was shooting different ammo.
The discrepancy was significant, I can’t say exactly how much but will photograph my targets this week.

Could be shooter error, but weird that the discrepancy was very similar in amount between 2 shooters.

Zahnarzt

Discussion Starter · #6 · 4 mo ago

Checked the screws in all 3 pistols…none were loose.

The only change I can think of was the ammo.

oldnrusty38

· #7 · 4 mo ago

Zahnarzt said:
Checked the screws in all 3 pistols…none were loose.

The only change I can think of was the ammo.

Good that you are narrowing it down, need to figure out difference in POA/POI. An inch? A foot? 7-10 yards is not very far, for a 10 yard zero you may be a fraction of an inch low POA/POI at 7 yards.

What ammunition? If you have any remaining ammunition from older range trips I would also shoot that and see if you are getting the same shift as the new ammunition.

Reactions: 2

azpoolguy

· #8 · 4 mo ago

I didn’t have to re zero my RMRs for three years even after removing it for the yearly battery change.

No change of zero on my 508t and a thousand rounds.

remanaz

· #9 · 4 mo ago

I have several dots and haven't had to readjust them. Ammo changes haven't been a problem for my pistols but it definitely cause poi shifts on rifles.

Large velocity differences could cause shifts. Hitting lower might be due to a lower power factor ammo or a heavier bullet. Was the ammo reloaded ammo? Or a heavier grain bullet?

Reactions: 1

Rich J

· #10 · 4 mo ago

One more thing is what distance you zero'd the optics at, vs. what range you were shooting when you noticed the problem?

If you were seeing hits low, and the distance was closer than zero, this would be correct. As you move the target closer in on a zero'd optic, but keep point of aim centered, your rounds are in fact going to be lower on the target itself.

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Reactions: 1

Zahnarzt

Discussion Starter · #11 · 4 mo ago

Just saw this and found it interesting considering 2 of the optics I am having an issue with are both Vortex Venom.

oldnrusty38

· #12 · 4 mo ago

Zahnarzt said:
Just saw this and found it interesting considering 2 of the optics I am having an issue with are both Vortex Venom.

You are also having an issue with a holosun correct?

Did not want to say it up front but I would get away from vortex and replace with a holosun or trijicon but that can be an expensive proposition.

Zahnarzt

Discussion Starter · #13 · 4 mo ago

oldnrusty38 said:
You are also having an issue with a holosun correct?

Did not want to say it up front but I would get away from vortex and replace with a holosun or trijicon but that can be an expensive proposition.

Yes, but not to the same degree. I haven’t had a chance to try to resolve any of the issues yet, but am going to work on it tomorrow. Planning to swap my Vortex optic over to a 22LR pistol with a picatinny rail, and move the optic on that one (Holosun 507C) to my Q5 SF.

I’m also going to remove the Holosun 507K on my P365, then place new Loctite and rezero.

I appreciate all the responses. I’ll post a follow up once I’ve made a few changes.

Jon

oldnrusty38

· #14 · 4 mo ago

There should be a way to return the optic back to factory '0', I would do that then start your re-zero from there. Good luck.

Illinois Sucks

· #15 · 4 mo ago

You said you reach the full extent of downward adjustment? It's possible the optics adjustment screws were over torqued and got screwed up. Send them in to Vortex and they'll either fix 'em or send you new ones for free. Great company.

Zahnarzt

Discussion Starter · #16 · 4 mo ago

Apparently I’m not the only one having problems with elevation adjustments on Vortex Venom RDS. There are a whole slew of videos on YouTube about this. Like this one:

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