Almost looks like it was a 223 bolt that has been opened up. I dont see any part of the extractor groove.
The bolt he has problems with is the 2nd set of pics he posted.The extractor lip and rivet are clearly visible in the pictures...rivet is at 1:30 and the extractor lip at 5:00.
Ahhh....my mistake. Sorry. -AlThe bolt he has problems with is the 2nd set of pics he posted.