The reason I called a Hogdon Tech was that I tried it the other way, loading my favorite 2 3/4" load in a 2 1/2" hull, but with a shorter wad, and about blew up an old Baker, had a dickens of a time getting the gun open, and the primer fell on the floor when I did manage force it open. I believe the Hogdon guy's term was that the pressure would go up exponentially. Jim Pettengill