Anyone ever have their BUIS lose zero?

[lilred06]

Title says it.

About two or three months ago I zeroed the irons on my Spikes (a2 front and Magpul Pro rear) and zeroed a trijicon MRO. Fast forward to now, I put an Aimpoint PRO on that same gun, took it to the range to zero it and decided to check on the irons. They lost zero something fierce. They were zeroed at 25 yds, today they shot about 2” high and ~1” left. I confirmed this with other five shot group. All about the size of a quarter or so, all shooting at that position.

I re-zeroed them today when I zeroed the Aimpoint but anyone ever see this? Any ideas?

 

[cmshoot]

Title says it.

About two or three months ago I zeroed the irons on my Spikes (a2 front and Magpul Pro rear) and zeroed a trijicon MRO. Fast forward to now, I put an Aimpoint PRO on that same gun, took it to the range to zero it and decided to check on the irons. They lost zero something fierce. They were zeroed at 25 yds, today they shot about 2” high and ~1” left. I confirmed this with other five shot group. All about the size of a quarter or so, all shooting at that position.

I re-zeroed them today when I zeroed the Aimpoint but anyone ever see this? Any ideas?

Did they work their way slightly loose? Were you using the same ammo they were zeroed with originally?

 

[lilred06]

Nope they’re tight and using the same ammo. I got to thinking and I believe this may have happened: first time I zeroed the irons before I even mounted the MRO, this time I zeroed the irons with the Aimpoint already mounted, using the irons THROUGH the Aimpoint. I think this led to a POI shift due to a different presentation of the sights. Correct me if this isn’t how any of this works

 

[Kahrnut]

heat mirage

 

[lilred06]

heat mirage

Indoor range