After about 100 shots the POI is shifting...

"rcmark"Interesting shoot today.

Shooting at 105 yards, the first 3 mags shot well.
Filled the gun it started shooting 3" to the right.
Did 4 more shots and it was a good group but 3" to the right of the POA.
On the 6th shot POI started moving to the left.
By the 10th shot it was dead on again (POI = POA).

Click to expand...

Well with your new information it sure sounds like a expansion problem with the air tube and its effect on the scope mount even more. 

What is the pressure change from the first shot at fill to the tenth shot when it returned to POI? It would be very nice to connect an indicator between the scope mount and air tube.

I could lend you an indicator that would be needed to be clamp on the scope mount. You would most likely need to move/take off scope. USPS small flat rate box to get and ship back. You would need to have some mechanic experience. 

Scope Mount might want to be loosened and re-tightened to make sure the pressure is equal on the air tube between the contacts on them. 

 

Sorry, I might have referred to just scope mount but what I wanted to say is.

The mount that goes around the air tube and connects also the barrel there are 4 screws by a picture I am looking at.

And is there a screw or 2 that the scope rail uses to tighten up on that mount? 

Well if any of that is out of alignment that would not be good. When the screws are tightened do they seem to bottom quick and easy or do any feel like they are pushing or pulling metal and putting a pre-stress on that system? And it would not take much. That is what I meant to say.

It still seems as pressure is at fill the air tube is able to tweak that mount system. But as it lowers it goes back. Other wards one is fighting the other.

Well what a trip or better yet a waste of time.

Do you hear the wind on the mike?

Do you see your shirt floppy in the wind?

I thought you might have had a real problem. But after seeing this video that you have presented please disregard all other replies I made to your post except for the first.
No wonder you never responded to the different replies referring to WIND.

EDIT - Please put the same video back up so the rest can see for themselves!!

Where is this video? Did I miss it?