AWB isn't the only way to diss the 2nd. The 1st isn't the only amendment McCain has dissed. He got a F- from GOA in spite of his AWB vote and they claim his pro 2nd votes are pandering, that his votes on the 2nd come from momentary political advantage not from principles, i.e. the same thing the anti-Mitt folks say against Romney. If you want purity on the 2nd your only remaining choices are Huck and Paul, according to GOA. If you can't stand them because of other issues then you'll either have to accept less than purity on the 2nd, go 3rd party, or go pout in the corner. But to pick McCain over Romney on claims of 2nd amendment purity is short sighted.
If you can't trust your own analysis trust the enemies. NY Times loves McCain and hates Mitt.