Twice with my BAR. First time during a freezing sleet storm in Wisconsin, I was pretty careful all day long chipping ice off of the action and checking it every now and then, and in one of those " checking the actions" I didn' t realize that the bolt didn' t close all of the way because of ice being stuck in there.

Second time was durning a deer drive and a spent shell got caught in the action half stuck out. That pretty much took care of my second shot at a doe I missed with my first shot.