Jack Merrill: Hey Jack Jack, Are you running that new brass thru a F.L. resizing die first? A light crimp. And I do mean a lightly done one. Usually is sufficient for a 270 Win. And no. (crimping) it is not always done so on the bullets cannelure ring. I suggest strongly!! say within the guidelines of what the manuals say about C.O.L. Max & Min lengths. Do not worry yourself over Free Bore in a gun barrel for the time being. As you become more and more proficient at reloading you'll come to know and how? to deal with these different specific terms. One thing I will say about reduction of Free Bore done so on purpose? You increase chamber pressure dramatically!!! and >only at times< gain some really noticeable accuracy. Your 270 is more accurate than most other rifles you'll encounter right out of the box. Enjoy your rifle. But most of all >be safe with your reloads.
SSMcG