which caliber would the Lee die work with ?
It's universal, meaning its suppose to work with all calibers. Don't know if that's true or not but I haven't found a caliber mine doesn't work with.
Having said that, I haven't tried it on my 204s yet so I can't swear to that.
I normally do my decaping while sizing but the universal decaper does come in handy some times.
Well worth having on your loading bench.
A bit off topic but Lee also makes a universal expander die, that puppy comes in handy too. If you load cast bullets in rifle cases, a slight expanding of the neck allows the cast bullet to start without screwing up the brass.