apparently Phil uses .13 - .56 strings on his PC-1s. Wow, considering his playing style and tuning, that's really shocking to me. i've always loved his playing and tone through the years.
he talks about it at around 1:40
[VIDEO]http://www.youtube.com/watch?v=_FpaEdPuf-Q]YouTube - Total Guitar @ Download: Def Leppard's Phil Collen part 1[/VIDEO]
Yep, and his necks are built like baseball bats, too. The guy is also completely ripped, which is almost unheard of for a vegan.