All caliber conversion means is switching from one caliber to another. New shell plate(holder),tool head with dies and powder measure and powder funnel. There is one shell plate that will load several different cartridge. That is the plate for 45 acp as it can also be used to load 308,30'06,7 and 8 mm Mauser and any other cartridge with the same rim diameter
as 45 acp. I have 2 650s and my only complaint is that the changing of the priming arms is a real PITA,there's very little room to get a wrench or pliers in the space to remove the arm. I have a relative who is a tool maker and had him take a look at the set up and he couldn't come up with an easier way to change arms so I just bought a second machine . Easier to change machines than priming arms IMHO