Bad ammunition cracked a bolt and blew out a magazine of a Bushmaster ACR, showering the users hand with small pieces of copper. Otherwise the rifle was unharmed, which bodes well for the ACR design.

The user does not know the origin of the ammunition. It belonged to his friend who cannot remember where or when it was purchased. What is known is that it came from a old white Winchester box and that the brass had a Twin Cities headstamp.

More photos of the rifle are here.

[ Many thanks to Bret & jdun1911 for emailing me the link. ]