I don't know either, and I can only guess, but if I had to guess, since he is also on the board of directors of the NRA, I'd guess something in there bothered him, or he saw something in the bill that he doesn't like or has been used in a way he doesn't like.
I have alot of faith and trust in Senator Craig and his character and judgement, he is a true conservative and is privvy to more info then me, so I'm sure he has good reasoning, I just wish he would explain it and talk about it.
I did notice that the NRA isn't taking a stand on this either way, which is a nice way of giving alot of conservatives the okay to go against it.
I think its healthy for the bill to be debated, evaluated, and fine tuned, every so often (thank god for sunsets).
Some parts may need strenghting, and other parts may have been overly used.
Also, I am disgusted with the lock step opposition of the dems. It's delay for delays sake, meant to hurt the CIC, but possibly harming us all. That is pure vile partisanship, IMO.