Meat Hunter, the Dillon 550 uses standard 7/8" reloading dies. Changing calibers is relatively easy. With practice you can do it in 15-20 minutes including adjusting the powder measure. I can load 300 rds per hour of 45 acp at a leisurely pace to keep an eye on everything. The dillons work great for pistol ammo, and good for rifle ammo. There is a small sacrifice in accuracy when loading rifle ammo on any progressive press. Most of this can be overcome with attention to detail. The Dillon is a great machine and worth the money if you want to load lots of ammo.
Jason Moeller