In the spirit of the original post...
I had the "firing pin retainer plate" crack and release the firing pin (back at me) once. That stopped everything. See #30 on the diagram here... http://media.photobucket.com/image/b...=sevendaysview
And I've also owned a... wait for it... a Ruger
that failed as well. the ejector rod washer was split (#17) http://www.gunpartscorp.com/catalog/...spx?catid=8353
So both guns locked up tight and were unusable until I replaced the $2.00 and $5.00 parts. Both still work fine - years later - and are "trust worthy".
I get a kick out these guys who will not "tolerate" any kind of failure at any time. I buy guns from these guys all the time for next to nothing and repair them for pennies and the keep them or flip them. I count on the "never tolerate failure" crowd to keep me in guns for cheap.
If you are planning on never having a failure and never having to deal with one; you have a bad plan.
Mechanical things break, count on it.
DOUGH! - I voted incorrectly for "semi auto" and should have voted for both.