Are you sure about that? My Dillon started life as a 450 and several I upgraded it into a 550b. The "O" part of the press is all that changed. I have the roller handle upgrade (Dillon Brand) and it went right in the same hole! Call Dillon, either way they will have the part you need!

There were two roller handles available one was a metal and the other was the plastic. I don't thing the plastic is offered any more. (Shame on you!) there are more than two companies that offer them, but they are "Universal Fit" and have a smaller threaded section, so a bushing would be required!

I ended up using my original Dillon handle on my Rock Chucker Supreme press! The RCBS handle broke off one day, and I had the Dillon laying around, so I put it on. It is about 2 inches longer, and gives far more leverage, but the bottom of the handle stroke is a long ways down now!

Ivan

If you are looking for an aftermarket Roller handle