Can barrel mirage change POA?

[Vodoun daVinci]

I'm shooting literal bug holes at 100 yards the first couple 5 round groups. Then my zero starts to shift and groups start going high then by the 5th group they have opened up to 2 MOA and are 2" high at 100 yards. I was convinced it is me but I videoed myself and I'm not flinching nor doing anything different between 1 and 5.

I'm shooting at 40X and get significant barrel mirage....is it possible that the mirage is literally distorting my point of aim and shifting it?

VooDoo

 

[isofahunter]

Short answer is yes.
Back down power.
Longer cooling period.
Mirage barrel band.

 

[Vodoun daVinci]

Thanx! That was my next question....running the scope at lower magnification and not seeing the distortion/target displacement is a viable fix? Awesome....

VooDoo

 

[Dthomas3523]

Yes. But 2moa groups @100 is a bit much.

Get a mirage band/shield. That will answer question definitively.

 

[...]

by the 5th group they have opened up to 2 MOA and are 2" high at 100 yards.

VooDoo

so you will see vertical dispersion with mirage.......but your groups shouldnt "open up".

you should essentially be shooting the same size group, just higher on the target.

theoretically your groups can "open up" if you have a lot of switching wind, that is blowing the mirage around.....but i personally have never seen that.


i suspect its a combination of mirage with some other issue.

 

[hlee]

so you will see vertical dispersion with mirage.......but your groups shouldnt "open up".

you should essentially be shooting the same size group, just higher on the target.

theoretically your groups can "open up" if you have a lot of switching wind, that is blowing the mirage around.....but i personally have never seen that.


i suspect its a combination of mirage with some other issue.

If the mirage is heavy, it could be swirling around the aim point on the target such that it is no longer a distinct spot. This would cause variability in the actual aim point and could cause the groups to open up...

 

[Vodoun daVinci]

I am absolutely positive now that all of this is target displacement caused by barrel mirage. The image is barely blurred in the scope - not enough to alarm me. But the target is displaced significantly and gets worse the hotter the barrel gets. 1 st two 5 round groups are literally .75 MOA - last three groups get progressively worse from 3 to 5.

I'm testing again Thursday and we'll see but I am positive that this is all target displacement by hot air. My cold bore shots are always awesome or were with my 6-24X50 Vortex Crossfire and now I have this new Athlon 10-40X56 and the glass seems to see right thru the mirage that caused blurriness before. But the image is definitely not representative of where the target actually is.

VooDoo