I mount it in the drill press head and adjust it to fit exactly inside the case mouth and lock it down solidly.

Then I adjust it until it will cut just a little of the brass off the case.

Trial and error will get us to the place where it trims them to at least 2.484 or less.

Once adjusted, I lock it down and am ready to process all the cases.

I use the slowest speed on my drill press, as it is plenty fast enough for these operations and there is no big hurry.