One time a dad, his adult son and I were deer hunting out of a tent. Came back from the morning hunt and unloaded our rifles. I watched the son unload his dad's rifle, old Remington pump model 14 in 35 Remington calibre. After he had the ammo out of the tube magazine, I watched as he gave it two extra pumps. He then handed the rifle to me, because I wanted to look at it.
I again pumped it and looked in it. I asked if I could try the trigger and said I could. I then gave it another pump, aimed at a rock on a hillside, squeezed it off, and BANG! That is a surprise you don't want to get. My immediate reaction was fright, because we had permission to hunt on a ranch and there were cattle all over the hill I shot into. Could a glance off the rock or bare, frozen ground have hit one?
Not long after that I read where one had to be careful with the model 14 in 35 Remington, because the last cartridge in the magazine sometimes hangs up!
About the same time as this there were a group of us deer hunting from several camping outfits. Again, after teh morning hunt, an older fellow was sitting on the ground, back against a vehicle wheel, unloading his 8mm Mauser, by working the cartridges through the chamber. I was about a hundred feet away.
BOOM!
He obviously wouldn't have the bolt handle down in the shooting position, while just unloading the magazine. I'll guess that he too, thought it was empty and was clicking on an empty chamber. We never did find out.