I don't know about those .223 answers... I have shot a full unopened soda can at 600yrds and it did not go all the way through. The bullet was kick out the same hole it went in. I would suggest a 6mm myself.
Ray
If outer space shots count then there is one more that is the fastest. I think that is was just over 25,000 fps. It was in popular sience a while back.
Ray