Went to chamber a round in my 1911 22  and it went off.  I knew damn well I had not had my finger on the trigger so I tried to duplicate it and couldn't.  When I examined the hull I found not a mark on it. Underscores why you always make sure the weapon is pointed in a safe direction.  Anybody else ever have a 22 spontaneously detonate on loading?  this was Federal HP

I had a Colt .22 lr conversion for my Colt 1911 back in the late 1970s.  The first time I took it too the range and chambered a round, it went full auto until the magazine was empty. There was not a single firing pin indentation on any of the cases after three magazine of the same malfunction. Apparently the wrong spring was in the box. I had bought it used. I "tuned" the spring until it would reliably NOT slam fire when the slide went into battery... and promptly traded it off!