ORIGINAL: Buckeye Mike
I am not an expert in physics but I do know that when I take my warm camera into the cold to take a picture I get condensation on the lense. Also, since warm air can hold more moisture than cold air it would seem to me that taking a gun or any other object from the warmth to the cold would squeeze the moisture out of the air surrounding that object and thereby create condensation. Again, I am no expert.
ORIGINAL: livbucks
You WILL NOT get condensation taking a warm rifle outside in the cold.
You WILL get condensation taking a cold rifle inside a warm house.
Some people will leave their guns outside if they are going back out soon.
What you are saying is contrary to the laws of physics. Condensation forms out of warm moist air that comes in contact with a cold enough surface. Take my eyeglasses for example. When I leave the house on a very cold day, no fog forms on my lenses. When I return to my warm house with freezing cold lenses, they fog completely to the point I must remove them until they warm up. I have never had my scope fog when going to the outside on a cold day but it will always fog when retuning to camp with a cold gun. If fog formed on your scope when you went outside on a cold day, the fog would soon enough freeze and your hunt would be a tough one. I've never had that happen. Good thing...