When fire-forming factory new brass, is it best to fire-form with HOT loads or mid level loads with mid burn rate powder for best/most consistent results? Thank you for your answers
If you are fireforming for the actual caliber the brass was made for, use your regular load. Notice the brass will probably grow for the first 3 firings.
If you are forming one caliber brass to a different caliber, I always go lighter. It is all going to depend on what caliber and what you are forming it to.