Night Vision PVS30 POI conundrum

[m1ajunkie]

So I've been out playing with my PVS30 the past couple nights and it has me scratching my head. At distance, the PVS30 is pushing my impacts high while at 100 yds I am seeing basically zero shft in my zero. Last night, I ran through my targets and checked my dope in the daytime then put the PVS30 on and did the same exercise, see target pics below.

How can I see essentially no zero shift at 100 yds, but then have a .3/.4 high shift in POI at extended distances? Am I missing something in my setup or could I be seeing some kind of parallax error?

100 yards- daytime on the left, nighttime on the right...... not sure what the fliers are about but I'm sure it's me

627 yards- notice impacts on top side of plate

835 yards- all impacts grossly high here

 

[Evolution 9]

If we assume (risky) that there are no other variables messing with your shots, then the demagnification is incorrect on the 30. I’d strongly lean towards something else with your setup, but if it’s the 30 doing it, incorrect demagnification is the only mathematically possible way to get good hits at 100 and not at distance.

 

[CoryT]

I would not rule out parallax error. Did you try moving around behind the scope to see if you detect any movement? Are the 30 and rifle scope in the same plane?

 

[m1ajunkie]

@CoryT - The scope and the PVS30 are directly inline with each other, so I would say in the same plane. I only did a brief parallax check on the 630 yard target and didn't see any error. That said, I'm not really able to use my parallax knob like a true parallax knob, I basically have to set it where the PVS30 image is clear..... if I remember correctly the manual calls for parallax to be set to the infinity position but I have to back off of that slightly to get a clear image. This is why I'm wondering if I'm having some kind of parallax issue.

@Evolution 9 - any guidance on how to check the demagnification theory? I'm planning to go back out tomorrow night and do some more thorough testing and gather more detailed information on the error I'm seeing. I've actually noticed this issue on 2 different rifles with 2 different scopes using the same PVS30. I plan to test and document 2 rifles and see if they both show the same error.

 

[Evolution 9]

All that comes to mind is 2 box tests at 100 yards. One with day scope only, and one with the PVS30. If one box is significantly larger/smaller then that would be the answer.

Obviously, any variables you can control will improve the quality of your resulting data.

Again, I’ll be surprised if that’s the issue. Usually stuff like this has an “oh duh!” answer that’s related to some other part of the process.

A friend recently asked me why all his DOPE was perfect to 1200 yards, but somehow his 300 yard shots were consistently 9” high…Within a week,he figured it out and won’t tell me what it was. Whatever it was has him so embarrassed in it’s simplicity that he won’t tell me

 

[newguy2k3v2]

What if you zero up on paper at 100 with and without the 30 and then shoot paper again w and w/o at 100 with your ex.800yd dope dialed to see if it’s something happening with adjustments dialed or with distance?

 

[m1ajunkie]

@Evolution 9 & @newguy2k3v2 good call on the day/ night box testing. That's something fairly easy to. I didn't mention it earlier, but I'm using a T3 reticle and holding in the reticle vs dialing..... I don't think that would matter as in theory whatever is happening should show up in a 100 yd box test if I test the same way I'm shooting.

Hopefully I can get something figured out because it's a total head scratcher.

 

[Conqueror]

Would also see if it’s true when you use holdovers versus when you dial.

 

[TheHorta]

Do you have an IR laser? You can fiddle that to determine POI / zero at distance. Mount PVS-30 and fiddle with paralax until POA and laser align.

 

[m1ajunkie]

Do you have an IR laser? You can fiddle that to determine POI / zero at distance. Mount PVS-30 and fiddle with paralax until POA and laser align.

Yes I'm using a raptar..... I didn't even think about using the IR laser to see differences in poa/ poi, very good idea. Thank you!

 

[newguy2k3v2]

You could try a small piece of reflective tape for your nv aimpoint also. Just a little bit of IR gives you as good a poa as you’ll ever get in daylight. Just another way to refine the troubleshooting process.

 

[Killswitch Engage]

ill say something and it may sound unbelievable but i have seen mirage at night using a clip on in high heat......

 

[TheHorta]

ill say something and it may sound unbelievable but i have seen mirage at night using a clip on in high heat......

Not unusual. See it on hot suppressors too.

 

[m1ajunkie]

ill say something and it may sound unbelievable but i have seen mirage at night using a clip on in high heat......

Very fair..... I am shooting suppressed and had put a number of rounds through it.

For what it's worth, I went back out Saturday night to test the shift again. This time, 100 POI had essentially no shift and when I tested at 810 yards, no shift. Must be something else going on and after saturday night I'm less concerned.