When it gets hot..
I have always had the gun set close'ish to the legal limit so with any great change in air temp and always chrono the gun to make sure it is legal. As long as the gun is running to the same levels then the aim points are fine. May not be required, may be work I need not do but I do it and i seem to shoot more consistently now.
He came, he shot, he made a bloody fool of himself!
Air Arms S400 with Menace 10 x 42 scope
Remember in life there are always two sides to every view and both are just as equal and correct.