If I didnt live in the country, I might be concerned about being seen standing in an open window, pointing a scoped rifle outside, (bolt open or not)! ;^0
But I do so I'm not. I generally sit on my back porch with a loaded shotgun and .22 in the evenings, on the off chance I need to kill something that day. I'll never understand how the crows know, but they do...
I live in the suburbs and I have a international parking sign[red circle and slash] about 200 yards away. I don't have to have the lights on in the house when I do this and I'm not exactly at the window. I have set up rifles on the dining room table and bore sighted on occasions. I'm half way across the room from the windows when I do this and the bolt is out even when I'm practicing. After cleaning and before the bolts or bolt carriers on the AR is reinstalled is a good time to practice. With the Garand, you can keep the chamber flag in the action just to be safe.