rifleman,
Are you talking about a manual trimmer like the Wilson, or the RCBS Case Prep Centre which is mains powered?
If the main poweder one, it should say on it if its meant for use with American 110V mains or British 220V...
If it has a 2 pin plug, I suspect its meant for 110V, and you would need a voltage adaptor to use it in our 220Vs..
Regards,
Peter