Using BUIS as a way to check RDS zero

[ABNAK]

So we all know EOTech has acknowledged a thermal shift of zero, but it can happen with Aimpoints too (albeit to a lesser degree). The thermal shift doesn't reset itself either when the temps return to the same as when zeroed.

So I was thinking about using the BUIS as a way to re-check zero prior to firing. Most here know about "getting on paper" with an already zeroed set of BUIS (which don't shift because of temps) and a RDS; just move the dot to sit right on top of the front sight post while looking through the iron sight picture. Gets you pretty close and then you fine-tune it by shooting.



Problems:

1) An iron sight picture is "subjective" at best, and can vary ever-so-slightly from one take to another.

2) I have personally seen the "get on paper" technique with the dot right on top of the FSP be a little different than after I actually zeroed the RDS. That is probably due to #1. Once actually zeroed the dot might be a little off to one side or the other or higher/lower (and I mean just a LITTLE, but it makes a considerable difference at distance) than with the co-witnessed "on paper" technique.





Thoughts for re-checking RDS zeros? If it is a range trip no biggie, you just re-zero/fine-tune it. But if you had to grab-and-go (real world scenario) with no time to re-confirm zero, what would you suggest? A 2 MOA shift can mean missing a target at 200m, or missing a tight shot at 100m (think a target partially exposed, not a COM shot).

[B52U]

I think you have covered the major issues. Good for a rough close zero check at best due to the subjectivity and slightly offset zero each of the sighting systems can have in relation to each other.

[Eurodriver]

I buy quality kit and beat the shit out of it so I know what it is capable of.

How many guys have actually driven their rifles over with a 5000lb SUV? Thrown it like a frisbee into some trees? Stomped on it in a few inches of muddy water?

Let’s be real - unless you don’t know what you’re doing when installing optics (very likely given people’s idiocy) or you buy less trustworthy optics like the MRO or a Holosun your zero is never going to shift when you grab it out of the safe.

And while we’re on the subject - You’re never going to use a rifle to defend yourself at distances a zero shift would matter anyway. Who gives a shit?

[ABNAK]

I buy quality kit and beat the shit out of it so I know what it is capable of.

How many guys have actually driven their rifles over with a 5000lb SUV? Thrown it like a frisbee into some trees? Stomped on it in a few inches of muddy water?

Let’s be real - unless you don’t know what you’re doing when installing optics (very likely given people’s idiocy) or you buy less trustworthy optics like the MRO or a Holosun your zero is never going to shift when you grab it out of the safe.

And while we’re on the subject - You’re never going to use a rifle to defend yourself at distances a zero shift would matter anyway. Who gives a shit?

Mental exercise, sufficient?

To play along, my driveway is 1/10th of a mile long. Someone shooting at me in front of my house from behind a car door at the end of the driveway could present the kind of shot I'm talking about: a POI shift could hinder proper shot placement. Not that I'm going to re-check zero before arming for such a situation, but a way to occasionally re-check it as the seasons change for instance.

I mentioned EOTech and Aimpoint. Those and ACOGs comprise my non-iron sight alternatives. No Holosun, no MRO.

[MegademiC]

Mental exercise, sufficient?

To play along, my driveway is 1/10th of a mile long. Someone shooting at me in front of my house from behind a car door at the end of the driveway could present the kind of shot I'm talking about: a POI shift could hinder proper shot placement. Not that I'm going to re-check zero before arming for such a situation, but a way to occasionally re-check it as the seasons change for instance.

I mentioned EOTech and Aimpoint. Those and ACOGs comprise my non-iron sight alternatives. No Holosun, no MRO.

Chest-shot through the car door is the superhero move.
Or just hunker down while they waste ammo and file insurance claim for the damage and file police report. Why are people doing drive-by’s in the sticks?

Even if it did happen, and you HAD to kill them. They have to come to you, theres not a team of snipers surrounding your house ( if there is, youre just dead), so wait till they are at 50yds and mag dump them. Might as well drill that third hole while they advance cause at this point youre either Jason Bourne or Shawn of the Dead.




Tldr: irons get your really close, range time gets you confidence and fine tuning.