Gt40: I was lucky and was able to retire at age 49 - I am 61 now and one of THE greatest benefits of being retired, I think, is being able to shoot for accuracy (load testing, sight-ins and serious bench work) only on dead calm wind condition days!
I have not shot for group size on a windy day in so many years (more than 12 years now) I have forgotten how frustrating and wasteful an endeavor that can be!
Like someone else posted, just as day fades away, so it seems, does the moving air.
I have two ranges for my accuracy shooting - one is a public range with no closed hours and the other is a private range belonging to a good friend of mine - again NO closed hours here.
The break of day is another time when the air is very often dead calm hereabouts.
Your targets are pretty impressive by the way, for 200 yard groups in poor conditions!
If its hot down your way then try that early morning shooting, less heat caused image distortion and hopefully less wind as well - if thats at all possible on your range.
Again best of luck with the new Rifle!
Hold into the wind
VarmintGuy
