Okay, so I'm playing and I got all of them up til Chapter 8. I missed the first one in Chapter 8 and Im at the 2nd one. Is there any way I can go back to the start of chapter 8 and get it without messing anything up and losing my progress on hard?
Once you finish a chapter, you can just go back and replay it from the chapter select menu. You'll need to replay some chapters several times on each difficulty level (inc Crushing, once you finish the game on hard) to find all the Bounties, as well.