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.

I've only noticed a big problem with ball powders..they will drive you crazy with temperature change......I will never use them again in any firearm...great groups and lots of problems is my take on them..never really noticed enough of change to matter all that much with everything else..

I've realized for a long time that temp. changes (80-90 deg. vs. 20-30 deg.) will almost always cause POI change with most powders. This is a huge reason to re-check a super load that you worked up in August if you plan on using it in Nov./Dec., or vice/versa. Some seem to be more prone to this than others, but I still feel they all show some susceptibility.
What I never paid attention to, however, was the humidity factor. I guess that's something I'll watch and record from now on. Been doing this stuff for a long, long time and never took that into consideration. Must have something to do with the air density factor, such as re-zeroing for a high-altitude hunt.

Yay for 20% humidity desert areas I hunt in!

Too bad temps fluctuate 40 degrees during the days in the fall...

Thanks for the info, good to know.

here in az to test temp sensitive powders some guys I talk to will throw a few loads on the dash of their car on a 100+ degree day for a few hours then go pop them off to see if the load will be ok in extreme tempatures