Kelly Timoffee
If you have a stock factory rifle much of what you are doing is wasted time if your full length resizing, and I full length "ALL" my cases. Too much of what bench rest shooters do to their brass is filtering down to us with bone stock factory rifles, these bench rest shooter have custom rifles with custom chamber and possibly custom made dies. The FTR shooters buy Lapua brass and do very little to their brass and "FULL LENGTH RESIZE" their cases.
When you full length resize the base of the case is supported by the bolt face and the front of the cartridge has the bullet supported by the throat of the chamber. This means the body of the cartridge and the neck never touch the chamber walls and this reduces the cases influence on aligning the bullet with the bore. Meaning the effects of neck runout and alignment of the body of the case in the chamber, the brass case is never perfectly made with the exact same wall and neck thicknesses.
Below a full length resized cartridge case in a factory made rifle is supported by the bolt face and the bullet in the throat.
Below you can neck turn your cases till the cows come home and it still will not fix poorly made brass with unequal wall thicknesses.
You can also put a STP sticker on the side of your car and it will not make it go faster.

You can also neck turn all your cases and it doesn't mean your rifle will shoot any better. If your trying to shoot bug hole groups then your going to have to pay more for a custom made rifle and extreme accuracy.
I'm not trying to talk you out of neck turning, "BUT" there is a reason why competitive shooters buy Lapua brass and not use American made Remchester brass and you can't make a silk purse from a sows ear. And you will not see people winning bench rest competitions with bone stock factory rifles.
If you want to neck turn your cases you need a neck thickness gauge like the one pictured below to be able to sort through your brass for "worthy" cases worth neck turning.
You then need a good runout gauge to check your sized and loaded cases for runout.
Without these two type gauges you will not know if your brass is even worthy of neck turning, also note that the U.S. military considers .003 or less runout match grade ammunition.