Many times. Never was an ammo problem for me, just a nut loose behind the stock.
Once I forgot to chamber a round after climbing into my stand. A little fork-horn just stared at me after the 'click'. When his head was behind a tree I was able to chamber a round and drop him.
It's also happened several times with a Benelli. If you don't let the bolt fly forward with authority, it won't go into battery and will fail to fire. I've done this on two turkeys. One let me chamber a round and kill him. The other didn't. I've developed the habit of using the bolt handle as a forward assist. Funny that the Benelli is supposedly superior but my 11-87 has never had the same problem. It slams shut like it has some nutz. /rant
To a much greater extent than most mechanical devices, firearms are terribly unforgiving of any overconfidence, complacency or negligence.