AGS,
Yes, sometimes a little slop does come in handy. I was fortunate enough a couple times to buy once fired cases from a firearm manufacturer and had way more 7x57R cases than 8x57R cases and made up some 8x57R cases using the 7mm ones. They were close enough that "polishing" rather than "turning" the head diameter (after sizing as much as possible) allowed their use. A lathe, where I worked made things easier, without access to a lathe, a drill press would also work. BTW, this exercise is what taught me the difference between the cases.
Mike
