I use a couple different ones, just because they're slightly different sizes.  I generally use a Lee set so that I don't move the shoulder back, what some call partial full length sizing.  I also have an old Hollywood Gunshop full length sizer that is close to being a small base die.  I have one barrel that has a tighter chamber than the rest and I use the Hollywood when loading for it.  And, there's times I use 7.5x55 collet die for neck sizing.