While I understand the OP's misunderstanding of my original post, he clearly missed my meaning. What you need is the flipping brass you're going to use, and measure a seated bullet in it, just as Redding said. But this bushing size is only good for that lot of brass and may or may not work with other brass should you purchase more downrange. It can be virgin brass, though I generally prefer to use once fired brass for any measuring, because it's far more consistent than virgin brass in terms of wall thicknesses, diameters, and the like.
Ultinately, I don't use bushing dies for hunting rifles, as field accuracy of 2MOA is plenty good enough to kill deer out to my personal limit of 500yds, and every one of my rifles will do under 1.2MOA without resorting to bushing sizing. If I started shooting out to 1000 or beyond (at targets) I'd consider bushing dies if I ran into problems with load precision.