Yesterday I killed a deer at somewhere between 300 and 400 yards. I was curious how far exactly and left the deer in the road and went back to where I had shot from. The range finder wouldn't give a reading. I picked the deer up and placed a bright yellow grocery bag on a weed. I couldn't get a reading from the bag. Thinking maybe the aiming square wasn't sighted right, I moved to the right and got a reading of 337 from brush and weeds on the edge of the road, but I think it was reading closer to me than the deer had been. Apparently a plastic bag isn't reflective. Just what is a reflective target, or can a rangefinder be looking somewhere different from the aiming square?