Well, that clears up a few things. For a straight hunting rifle, one that wasn't set up with a tight neck, I'd probably not bother with the turning. If you're using brass that has noticeable dimensional problems in neck wall thickness, it may be of some use to clean it up a bit, but it'd be easier (and better) to use good quality brass to begin with. Another thing to consider with factroy chambers, the more you thin the necks, the more the necks will be worked upon each firing. Expanding to fill the chamber, being sized back down far enough to adequately hold a bullets, etc.. This will lead to reduced brass life, at least to some degree. The tube mic is a useful tool to have on your bench, regardless of whether you're turning or not. It will at the very least allow you to decide whether the brass you're working with even needs such treatment. If you want to give it a try, knock yourself out. At the very least, you'll learn a bit more about handloading, and that's never a bad thing. At best, you might just make questionable brass useable, and even see some accuracy improvement in the process.