Kate, There's two models of the Judge, My #3 son has both. One takes 3" shells and the other 2.5" shells. It can also use .45LC and I believe you can also use slugs! Kaboom! -- Dave G KK7SS Richland, WA '59 Morris Minor 1000 - working on it :| '65 Sprite - running :) '76 Midget - co-owned with #4 Son :) '06 Honda Civic Hybrid