This has happened to me on more then one occasion. Makes me want to give $5-$10 less because I have to clean their mess! I always clean mine before selling, thought that was just common courtesy.Here's one that makes me ! How about guns that aren't thoroughly cleaned before being sold on the classifieds? Or how about not being cleaned at all??
On another note, my father was sighting in his shotgun scope for deer season a couple years ago. Shoots a couple shots, adjusts, shoots again, looks up at me and has blood running down his forehead. His scope rings broke and kicked the scope into his head. Couple of band aids later, the only thing still hurt was his pride.