I just bought a used Dillon XL 650. The person that originally owned it had it setup for pistol calibers and did not have rifle dies. I have Lee dies for my rifles and was wondering if these dies can be used in this loader or would I have to buy the Dillon dies

No trouble at all
Here is the manual
http://www.dillonprecision.com/#/manuals.html

i like the lee carbide dies for a lot of my straight walled revolver cartridges.
i use most everything else as the seat and crimp dies.
i generally like to size and then tumble off press then prime and load on the press.

thanks

The only Dillon die you have to use is the powder die that holds the expander/funnel and mounts the Dillon PM.

Andy