The question that I tend to ask myself when presented such a statement is..."How many times in that 24 year period has he voted to deny our freedom?"
According to my (I'm a member) gun rights group, Specter has voted with us 55% of the time. Many of those votes are 'safe' votes, meaning that his vote 'with us' didn't effect the final outcome because it would have passed without his vote.
Thanks for the link. I gave up after ten minutes of looking.