Not sure how the humidity has affected your bolt, but, no doubt that is has. I went back and looked at my cheat section in my log book to clarify the temp, humidity issue. I still stand by what i said in my first post, but let me clarify some.

The Change in temp will affect POI from your zero. IF you zero in 40 Degree weather, and shen shoot in 80 degree weather, it should be APPROX 2 inches high. And the opposite if the temps werre the opposite.

The humidity thing still plays into effect. 20 % increasse or decrease equals about 1 inch either way.

If you are not seeing this, you also have to consider this. You might have zerod your rifle on a nice cool 60 degree day, with 10% humidity.You go to the range a month later and it is a nice balmy 80 or so degrees and about 40% humidity. the temp increase will raise your POI 1 inch (approx) and the higher humidity, will lower it just over 1 inch (approx) there is no difference. Very few people will check, and keep track of temperature, and humidity in any type of record.

So, it might be just for military ball powder, might not be. I use this as a rule of thumb will all my rifles with great success.

I hope that clarifies things just a little, or helps make a little more sense of it.

Good Luck.