Robb Flynn uses a baritone and Phill Demmel uses a regular 6 string. how does that work? does phill tune down his E to some extreme tuning?
he probably just gets a rediculous string guage, like 13-56
Both a baritone and a regular scale guitar are capable of tuning to C# standard/drop B
They both tune down to Drop B.
Some regular scale 6 string guitars are capable of drop-A.
If you have thick enough strings you can tune to almost anything you like. This does not mean it will sound as good as a baritone, though; case in point: didn't Meshuggah first record Nothing on regular scale sevens? And they were tuning to an F.
Have you tried wikipedia, it's suprisingly accurate when it comes to anything metal related.